See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/220037484 Revised Effective Ionic Radii and Systematic Study of Inter Atomic Distances in Halides and Chalcogenides Article in Acta crystallographica. Section A, Foundations of crystallography · September 1976 DOI: 10.1107/s0567739476001551 CITATIONS READS 36,323 11,477 1 author: Robert D. Shannon University of Colorado Boulder 162 PUBLICATIONS 59,753 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: refractive indices and polarizabilities of minerals and synthetic compounds View project All content following this page was uploaded by Robert D. Shannon on 01 August 2016. The user has requested enhancement of the downloaded file. 751 Acta Cryst. (1976). A32, 751 Revised Effective Ionic Radii and Systematic Studies of Interatomie Distances in Halides and Chaleogenides BY R. D. SHANNON Central Research and Development Department, Experimental Station, E. L Du Pont de Nemours and Company, Wilmington, Delaware 19898, U.S.A. (Received 30 October 1975; accepted 9 March 1976) The effective ionic radii of Shannon & Prewitt [Acta Cryst. (1969), B25, 925-945] are revised to include more unusual oxidation states and coordinations. Revisions are based on new structural data, empirical bond strength-bond length relationships, and plots of (1) radii vs volume, (2) radii vs coordination number, and (3) radii vs oxidation state. Factors which affect radii additivity are polyhedral distortion, partial occupancy of cation sites, covalence, and metallic character. Mean NbS+-O and Mo6+-O octahedral distances are linearly dependent on distortion. A decrease in cation occupancy increases mean Li+-O, Na+-O, and Ag+-O distances in a predictable manner. Covalence strongly shortens Fe2+-X, Co2+-X, Ni2+-X, Mn2+-X, Cu+-X, Ag+-X, and M - H - bonds as the electronegativity of X or M decreases. Smaller effects are seen for Zn2+-X, Cd2+-X, In3+-X, pb2+-X, and TI+-X. Bonds with delocalized electrons and therefore metallic character, e.g. Sm-S, V-S, and Re-O, are significantly shorter than similar bonds with localized electrons. Introduction Procedure A thorough and systematic knowledge of the relative sizes of ions in halides and chalcogenides is rapidly being developed by crystal chemists as a result of (1) extensive synthesis within certain structure types, e.g. rocksalt, spinel, perovskite and pyrochlore; (2) preparation of new compounds with unusual oxidation states and coordination numbers; and (3) the abundance of accurate crystal structure refinements of halides, chalcogenides, and molecular inorganic compounds. A set of effective ionic radii which showed a number of systematic trends with valence, electronic spin state, and coordination was recently developed (Shannon & Prewitt, 1969, hereafter referred to as SP 69). This work has since been supplemented and improved by studies of certain groups of ions: rare earth and actinide ions (Peterson & Cunningham, 1967, 1968); tetrahedral oxyanions (K~ilm~in, 1971); tetravalent ions in perovskites (Fukunaga & Fujita, 1973); rare earth ions (Greis & Petzel, 1974); and tetravalent cations (Knop & Carlow, 1974). Further, the relative sizes of certain ions or ion pairs were studied by Khan & Baur (1972)" N H + ; Ribbe & Gibbs (1971): O H - ; Wolfe & Newnham (1969): Bi3+-La 3+; McCarthy (1971): Eu2+-Sr2+; Silva, McDowell, Keller & Tarrant (1974): No 2+. These authors' results have been incorporated here into a comprehensive modification of the Shannon-Prewitt radii. In this paper the revised list of effective ionic radii, along with the relations between radii, coordination number, and valence is presented. The factors responsible for the deviation of radii sums from additivity such as polyhedral distortion, partial occupancy of cation sites, covalence, and metallic behavior (electron delocalization) will be discussed. The same basic methods used in SP 69 were employed in preparing the revised list of effective ionic radii (Table 1). Some of the same assumptions were made: (1) Additivity of both cation and anion radii to reproduce interatomic distances is valid if one considers coordination number (CN), electronic spin, covalency, repulsive forces, and polyhedral distortion.* (2) With these limitations, radii are independent of structure type. (3) Both cation and anion radii vary with coordination number. (4) With a constant anion, unit-cell volumes of isostructural series are proportional (but not necessarily linearly) to the cation volumes. Other assumptions made in SP 69 have been modified: (1) The effects of covalency on the shortening of M - F and M - O bonds are not comparable. (2) Average interatomic distances in similar polyhedra in one structure are not constant but vary in a predictable way with the degree of polyhedral distortion (and anion CN). Both of these modified assumptions will be discussed in detail later. The anion radii used in SP 69 were subtracted from available average distances. Approximately 900 distances from oxide and fluoride structures were used, and Table 2 lists their references according to CN and spin. These references generally cover from 1969 to 1975. The cation radii were derived to a first approximation from these distances, and then adjusted to be consistent with both the experimental interatomic distances and radii-unit cell volume (r 3 vs V) plots, as in A C 32A - 1 * Polyhedral distortion was not considered in SP 69. 752 REVISED EFFECTIVE IONIC RADII IN SP 69. Although such r a v s V plots are not always linear (Shannon, 1975), their regular curvilinear nature still allows prediction of radii. This system is particularly accurate for radii in the middle of a series, and least reliable for large polarizable cations like Cs +, Ba z +, and T13 +. Radii-volume plots were used by Knop & Carlow (1974) and Fukunaga & Fujita (1973) to derive radii of tetravalent cations. These radii were used along with experimental interatomic distances in deriving the final radii. Greis & Petzel (1974) derived rare earth radii in eight- and nine-coordination using accurate cell dimensions for rare earth trifluorides and distances calculated using the structural parameters of YF3 and LaF3. These radii were used in Table 1 after applying small corrections ( + 0.030 ,~ to lXLa3+, IXCe3+, 'Xpr3+, and ~XNd3+; +0.025 A to all other Greis & Petzel ~XRE3+ radii, and 0.015 A to all HALIDES AND CHALCOGENIDES VI"RE3+ radii) for consistency with experimental interatomic distances and radii-CN plots. Where structural data were not available or not accurate, plots of (1) radii v s unit cell volumes, (2) radii v s CN and (3) radii v s oxidation state, or combinations of these were used to obtain estimated values. Fig. 1 shows examples of radii-valence plots used to provide consistency between experimental radii and those anticipated from the regular nature of these plots. Cations whose final radii values were derived from both estimated values and experimental interatomic distances a r e : V l O s S + , VIOs6+, VIOs 7+, VlRe4+, VIRES+, VlRe6+, VIReT+, VIRh4+, vI1U4+, VIIUS+, and VIIU6+. Fig. 2(a)-(e) shows plots of radii v s C N . Generally, it was assumed that radii-CN plots for two different ions do not cross. Radii for 'VCu+, V'Cu+, IXRb+, VNi2+, VIIEr3+' vIIyb3+ ' WITb3+ ' X.Nd3+ ' IVCr4+' Table 1. Effective ionic radii CR crystal radius, IR effective ionic radius, R from P vs V plots, C calculated, E estimated, ? doubtful, * most reliable, M from metallic oxides. ION EC CN AC÷3 6P 6 V l A G ÷ I 4D10 11 IV VSQ ~ AGed 60 9 AGe3 60 8 AL*3 2P 6 AM*2 5F 7 AM÷3 5F 6 AM÷~ 5F 5 AS+3 4S 2 AS+$ 3D10 AT÷7 5DIO AU÷I 5 0 1 0 AUe3 50 8 AU÷5 50 6 d +J 1S 2 8A÷~ 5P 6 BEe2 15 2 Ble3 65 2 vI Vll Vlll IVSO Vl IVSQ Vl IV v Vl Vll Vlll IX Vl VIII Vl Viii Vl lV vl Vl Vl IVSQ Vl Vl Ill I¢ Vl Vl Vii Viil IX X Xl XI! Ill IV l ~ Vl Vlll 81÷5 5 0 1 0 V l 8K+3 5F 8 Vl b K ÷ 6 5F 7 V l VlIl 8 R - I 6P 6 V l 8 R e 3 6P 2 IVSO 8R+5 45 2 I I I P Y 8R÷7 3010 IV Vl c e 4 15 2 l l I IV VI CA+2 3P 6 Vl • Vll Vlli x ~ Xll CDeZ 6 0 1 0 I V v Vl Vli Vlll Xll CE+3 65 1 V l Vll Vlll IX II CE÷4 5P 6 Vl VIll II C F * 3 bD I VI C F * 6 5F 8 V l 5P Ck 1.26 .81 1.14 1.16 1.23 1.29 1.36 1.42 .93 1.08 .81 .89 • 53 .62 .675 1.35 1.40 1.65 1.115 1.23 .g9 l.og .72 .675 .60 .76 1.51 .82 .g9 .71 .15 .25 .41 1.49 1.52 1.56 1.61 1.66 1.71 h75 .30 .41 .59 1.10 1.17 1.31 .go 1.1o .97 1.07 1.82 .73 .65 .39 .53 .06 .29 .30 1.14 1.20 1.26 1.32 1.37 1.68 .92 1.01 1.09 1.17 1.24 1.45 1.15 1.21 1.283 1.336 1.39 1.48 1.Ol 1.11 1.21 1.28 l.og .961 *IR* 1.12 R .67 1.00 C 1.02 1.09 C 1.15 c 1.22 1.28 .79 .94 .67 .75 R .39 .68 .535 * 1.21 1.26 1.31 .g75 R 1.09 .85 R .g5 .58 A . 3 3 5 Re .46 C* .62 A 1.37 A .68 .85 A .57 .01 * .11 * C .2T 1.35 1.38 C 1.42 " 1.47 1.52 1.57 1.61 C' .16 .27 * . 6 5 'C .96 C 1.03 Re 1.17 R .76 E .96 R .83 R .93 R p l.Vb .59 .31 .25 .39 A -.08 .15 P .16 A 1.oo 1.06 * 1.12 • 1.18 1.23 1.34 .78 .87 .95 1.03 c ¢ 1.10 1.31 1.01 R 1.07 E 1.163 R 1.196 R 1.25 1.36 C .87 R .97 R 1.07 1.16 .95 R .821R ION EC CN C L - I 3P 6 V l CL+b 35 2 l l l P Y CL÷7 2P 6 I V Vl C~÷3 5F 7 V l GHe6 5F 6 V l VIll CO÷2 3D 7 I V V Vl Vlll C0÷3 30 6 V l GO÷4 3D 5 IV Vl CR+2.3D 4 VI SP HS L5 HS kS HS HS L$ HS CR+3 3D 3 V l CR÷4 30 2 IV Vl Cg÷5 30 1 I V Vl VIll eRe& 3P 6 IV Vl c $ + 1 5p 6 V I Vlll lx X Xl Xll CUe1 3010 11 IV VI CUe2 30 9 IV IVSQ 1 CU*3 30 8 Vl 0 +1 15 0 I I 0Y÷2 6 F I O Vl vI I Vl I UYe3 6F 9 Vl VII Vlll IX E&e3 4 F 1 1 V l Vl 1 Vl I IX EU÷2 4F 7 V l Vll VIII IX x EUe3 4F 6 V i Vll Vlll IX F - 1 2P 6 i l Ill IV Vl F e7 I S 2 V l FEe2 30 6 IV IVSQ Vl VIII FE+3 30 5 I V v VI Vlll Vl IV Vl IV V Vl GD÷3 ~F ? V l FEe4 FEe6 FR*I GAe3 3D 4 30 2 6P 6 3010 kS HS H$ LS HS HS H$ LS HS HS CR 1.67 .26 .22 ,61 1.11 .99 1.09 .72 .81 .79 .885 1.06 .685 .75 .56 .67 .87 .94 .755 .55 .69 .485 .63 .71 .40 .58 1.81 1.88 1.92 1.95 1.g9 2.02 .60 .76 .91 .71 .71 .79 .87 .68 .04 1.21 1.27 1.33 1.052 1.11 1.167 1,223 1.030 1.085 1.144 1.202 1.31 1.34 1.39 1.44 1.49 1,087 1.15 1.206 1.260 1.145 1 .16 1.17 1,19 .22 .77 .78 .75 .920 1.06 .63 .72 .69 aT05 .92 .725 .39 1.9~ .61 .69 .TbO 1.078 ION fIR' 1.81 .12 *08 ,27 .97 .85 .95 .58 .67 .65 .765 .90 .565 .61 .40 .53 .73 .80 .615 .41 .55 .365 .69 .$7 .26 .44 1,67 1.76 1.78 1.81 1.85 1.88 .46 .60 .77 .57 .57 .65 .73 .56 -.10 1.07 1.13 1.19 .g12 .97 1.027 1.083 .ago .9~5 1.004 1.062 1.17 1.20 1.25 1.30 1.35 .g6~ 1.01 1.066 1.120 1.285 1.30 1.31 1.33 .08 .63 .66 .61 .780 .g2 .49 .58 .55 .665 .78 .585 .25 1.80 .47 .55 .620 .938 P • A R R R C R Re R• R E R R• R R ER c EG CN SP G 0 " 3 4F 7 V l l VIII IX GE÷2 45 2 V I GE*q 3010 I V Yi H e l 1S 0 I II H F * 4 "6F16 I V VI VII VIII HG÷I 6S 1 I l l VI HGe2 5010 I | IV VI rill HOe3 6 F 1 0 VI VIll IX X I :~ 8. ) v1 2.0. 5S IIIPY VI 1 ÷7 4D10 1V Vl IN÷3 6 0 1 0 I V .58 l.Og .56 .67 .76 Vl E E IR+J IR*4 IR÷5 K "1 50 50 50 3P 6 5 4 b * * ,6o Vlll Vl Vl Vl IV Vl VII VIII x 1.06 .82 .765 .71 1.51 1.52 1.60 1.65 1.69 1.73 1.78 1.172 1.24 1.300 1.356 1.41 1.50 .730 .90 1.06 1.ooi 1.117 1.172 .71 ~ Xll LAe3 4 0 1 0 V l Vl! vllI X I R R g R R R xli IS 2 IV Vl VIII LU*3 4F14 Vl Vlll 1X MG+2 2P 6 IV Ll÷l il R • 860 ll HN÷2 30 5 I V V Vl R R Vll lll MN÷3 30 6 ~ Vl A E Re c * R R• R R A * R* R HN÷6 30 3 l V Vl MN÷5 30 2 I V MNe6 30 l IV MNe7 3P b I V Vl MO+3 40 3 Vl MO*~ 40 2 Vl ~ o e 5 6D I IV Vl MO÷b 4P 6 l v • v VI Vll " :l 2, ) iv 2S Vl N N ÷5 I S 2 I l l Vl CR 1,14 1,193 1,247 ,87 .530 *670 --,26 -.06 .72 .85 .90 .97 1.11 1.33 *83 1.10 1.16 1.28 1.041 1,155 1.212 1.26 HS H5 LS H$ HS L$ HS 1.03 ...... .80 .89 .81 .970 1.04 1.10 .72 .72 .785 .53 .670 .67 .395 .3g .60 .83 .790 .60 .75 .55 .64 .73 .87 *IR* 1,00 1,053 10107 .73 ,390 *530 -,38 -.18 .58 .71 .76 .83 R R¢ A • R• : ,97 1.19 .69 .96 1.02 1.16 .901 1,015 1.072 1,12 220 .66 *g5 .62 k R R R ,. .53 .62 8oo. Re *g2 .68 E .625 R .57 E 1.37 1.38 1.66 1.51 1.55 1.$9 1.66 1.032 R I.IO l.lbO R 1.216 R 1.27 1.36 G .590 .7& • .92 C .8bl R .977 R 1.032 R .57 .720 .89 .66 .75 .67 .830 .90 .9b .58 .58 .665 .3g .530 .33 .255 .25 .66 .69 .650 .46 .61 .61 .50 .59 .73 1.32 .30 .... .044 .27 -.106 .16 .13 * G C E Re C R R Re R Re R A RH R R Re R* A A 753 R. D. S H A N N O N Table 1 (cont.) EC ION NA*I 2P 6 I V V VI VlI VIII IX XIl NB+J 4 0 2 V l N 8 , 4 4 0 1 Vl VIII N 8 , 5 4P 6 I V Vl VII VIII. ND+Z 6F 6 VIII IX N O + ~ 6F 3 V l VIII IX XlI N I ÷ 2 3 0 8 IV IVSQ v VI N I * J 3 0 7 Vl NI÷4 NO+2 NP÷2 NP*3 NP+6 NP+5 NPeb NP+7 o -2 OH-I 0S+6 0S+5 0S.0 05"7 0S,8 p .3 p *5 PA+3 PAt4 PA~5 P8+Z PB*6 p0÷l PD÷2 PO•J POe6 P~*3 PO÷4 POeb 30 6 5F16 5F 5 5F 6 5F 3 Vl VI VI VI V[ Viil 5F 2 VI 5F 1 V I 6P 6 V I 2P b I f Ill IV VI VIII 11 Ill IV Vl 5D 6 VI 5 0 3 Vl 50 2 V Vl 50 1Vl 5P 6 I V 3S 2 vl 2P 6 I V v Vl 5F 2 Vl 6D 1 V l • viii bP 6 Vl VIII IX 6 5 2 IVPY VI VII VIII IX x XI XIl 5 0 1 0 IV V Vf VIII 6 0 9 II 4 0 0 IVSO Vl 60 7 VI 40 6 Vl 6F 4 V l Viii IX 65 2 VI rill 5010 VI LS HS LS 1.13 1.14 1.16 1.26 1.32 1.38 1.53 .86 .82 .93 .62 .78 .83 .88 1.63 1.49 1.123 1.249 1.303 1.61 .69 .63 .77 .830 .70 .74 .62 1.26 1.26 1.13 1.oi 1.12 .89 .86 .85 1.21 1.22 1.26 1.26 1.28 1.18 1.20 1.21 1.23 .770 .715 .63 .685 .665 .53 .58 .31 .43 .52 1.18 1.06 1.15 .92 1.05 1.09 1.12 1.33 1.37 1.63 1.69 1.54 1.59 1.63 .79 .87 .915 1.08 .73 .70 1.oo .90 .755 1.11 1.233 1.286 1.08 1.22 .81 .99 1.00 1.02 I.IZ 1.18 1.26 1.39 .72 .68 .79 .68 .66 .69 .76 1.29 1.35 .983 1.109 1.163 1.27 .55 .69 .63 .690 .56 .60 .68 1.I 1.10 1.01 .87 .98 .75 .72 .71 1.35 1.36 1.38 1.40 1.62 1.32 1.36 1.35 1.37 .630 .575 .49 .545 .525 .39 .46 .17 .29 .38 1.0¢ .90 1.01 .70 .91 .95 .98 1.19 1.23 1.29 1.35 1.40 1.45 1.49 .65 .73 .775 .96 .59 .66 .86 .76 .615 .97 1.093 1.146 .96 1.08 .07 C RE C C E R• R• E R E R R R R A SP ~o.05~vi RA*2 R R* R E CN PR÷3 CF 2 V l Viii IX PR+4 4F I V I VlIl PT+2 5 0 8 IVSQ VI PT+4 5D 6 V [ PT+5 5 0 3 V l P U * 3 5F 5 Vl P U * 6 5F 6 V I Vl[l P 0 + 5 5F 3 v I 6P RB+L4P RE*~ RE+5 RE+O RE*/ 50 50 50 5P RH+3 RH+4 AHe~ RU*3 RU*4 RU*5 RO*/ RU*8 40 4D 40 40 40 40 40 4P VIII XlI 6 VI vll VIll IX X Xl xlI XlV 3 Vl 2 VI I Vl b IV Vl b Vl 5 VI 6 V[ 5 VI 6 VI 3 VI 1 IV 6 IV +6 3 5 Vl 5 .6 2P 6 IV vl 5 5 . 2 IVPY v vl $8÷5 4010 Vl 5 C ÷ 3 3P 0 v I VIII S E - 2 6P 6 VI S E * 6 6S 2 v I S E * 6 3D10 IV Vl SI.6 2P 6 IV vl $H+2 6F 6 VIl Vl I I IX SN*3 4F 5 v I Vll VIII IX Ill SN*4 4010 IV 58+3 E E RM E E E A * C e g c C C c C C E E R R VII VIII SR*2 4P 6 V l VII VIII IX ~lI TA*J TA*4 TA*5 R R k g R R A 5 0 2 VI 50 1 Vl 5P 6 V l VII VIII T 8 + 3 4F 8 VI VII VIII IX T 0 . 6 4F 7 Vl Vill vIIIV4+, IVpb4+, and XTh4+ obtained from these plots were used to help determine the values in Table 1. The first estimate of vIHV4+ was made from distances in C32H28SsV (Bonamico, Dessy, Fares & Scaramuzza, 19741. Another method used to estimate radii was based on the empirical relationship between interatomic distances and bond strengths. Brown & Shannon (1973) derived these relationships for the cations in the first three rows of the periodic table from a large number of experimental interatomic distances. These curves can be used to calculate hypothetical distances for cations in any coordination (Brown & Shannon, 19731 Shannon, 19751 Brown, 1975). Examples of cations whose radii were calculated in this way are: lVMn2+, V[Be2+, VtB3+ ' wps+, v l S 6 + ' V m M g 2 + ' and VmFe 2+. These are marked with a C in Table l. In certain cases, these values were combined with known structural data (see Table 2) to obtain the radii in Table 1. Although the A C 32A - I* CR ION eIRt 1.13 1.266 1.319 .99 I.IO .74 .99 .765 ,71 1.14 1.oo I,IO .88 .99 1.126 1.179 .85 .96 .60 .80 .625 .57 1.00 .86 .96 .76 .85 .71 1,62 1.86 1.66 1o70 1.75 1.77 1.80 1.83 1.86 1.97 .77 .72 .69 .52 .67 .805 .74 .69 ,82 .760 .705 .52 .50 1.48 1.70 1.52 1.56 1.61 1.63 1.66 1.69 1.72 1.83 .63 .58 .55 .38 .53 .665 .60 .55 .68 .620 .565 .38 .36 .51 .26 .43 .90 .96 .90 .76 .885 1.OLO 1.84 .64 .62 .56 .40 .540 1.36 1.41 1.46 1.098 1~16 1.219 1.272 1.38 .69 .37 .12 .29 .76 .80 .76 .60 .765 .870 1.98 .so .28 .62 .26 .~oo 1.22 1.27 1.32 .958 1.o2 1.079 1.132 1.24 .55 • 830 .09 .95 1.32 1.35 1.40 1.65 1.50 1.58 .86 ,82 .78 .83 .88 1.063 1.12 1.180 1.235 .90 1.02 .690 .75 .81 1.18 1.21 1.26 1.31 1.36 1.46 .72 .68 .04 .69 ,76 .923 .98 1.040 1.095 .76 .88 R R R R R A R ER R E 1 R E RM E E R RM RM ER A • c A * R• Re P A • c * R* R E R R C R c E E R R R EC CN TC+4 4 0 3 V I TG*5 40 2 Vl TC+7 4P 6 I V Vl T E - 2 5P b V I TE+4 55 2 I l l IV Vl TE+b 4 0 1 0 I V Vl TH÷6 6P 6 V I VIII IX X XI Xll TI+2 30 2 Vl T 1 + 3 30 1 VI r l + ~ 3P 6 I V v Vl VIII 1 L * 1 6S 2 v l VIII Xll T L + 3 5D10 I V Vl VIII TM+2 4 F 1 3 V I VII TM+) k F l 2 V I viii IX 0 + J 5F 3 V I O ÷ 4 5F 2 V I VII viii IX Xll u +5 5F 1 V l vii U +b 6P 6 I 1 IV Vl Vll Vlll v * 2 30 J V l v . 3 3 0 2 Vl v +4 3 0 I v Vl VIII V +5 3P 6 I V v Vl w +~ 50 2 V I w +5 50 1Vl w +6 5P 6 IV v vl XE+8 4D10 IV vl Y +J 4P 6 v I VII Vill IX YB+2 4 F 1 4 VI Vll VIII Y8+3 4F13 Vl Vll Vlll IX I N * 2 3 0 1 0 IV v vI VIII Z R + ~ 6P 6 I V V Vl Vll VIII IX SP CR fiR* .783 .74 .51 ,70 2.07 066 .80 1.11 .57 ,7o 1.08 1+19 1.23 1,27 1,32 1,35 1.00 .810 .$6 .65 .745 .88 1.64 1.73 1.84 .89 1.025 1,12 1.17 1.23 1.020 1.13~ 1.192 1,165 1.03 1.09 1.14 1.19 1,31 .90 .98 .59 .66 .87 .95 1.00 .93 .780, .67 .72 .85 .495 .6o .68 .80 .76 .56 .65 .7~ .54 .62 1.040 1.10 1.159 1.215 1.16 1.22 1.28 1.008 1.065 1.125 1.182 .7~ .82 .880 1.04 .73 .80 .86 .92 .98 1.03 .845 .60 .37 .56 2.21 .52 ,68 097 .43 ,56 ,94 1.05 1.09 1,13 1.18 1.21 .86 .670 .42 .51 .605 .74 1.50 1.59 1,70 ,75 ,885 .98 1,03 l.Oq .880 ,994 1.052 1,025 .89 .95 1.00 1.05 1,17 .76 .84 .45 .52 .73 ;81 .86 .79 .640 .53 .58 .72 .355 .46 .54 .66 .62 .42 .51 .bO .40 .~8 .900 .96 1.019 1.075 1.02 1.08 1.14 .868 .925 .985 1.042 .0o .68 .740 .90 .59 .66 .72 .78 .8~ .89 AN ER A e G C RC • E C C E R• G C R• C a R RE R ¢ R R R R E Re E * E Re R* E R* * RH R * * Re R* R E R* E R R • * R* C R C R• * *, majority of radii were derived from oxides and fluorides,* some were taken from chlorides, bromides, iodides, and sulfides. For large electropositive cations with highly ionic bonds, very little covalent shortening is believed to occur and radii derived from these other compounds should differ only slightly from those derived from fluorides and Oxides. Examples are divalent rare earths such as Yb 2+ , Tm 2+, Dy 2+ , Sm 2+, Nd 2+ and the ions Am 2+, Ac 3÷, Np a+, and U 4÷. Another useful scheme for estimation of radii is the comparison of unit-cell volumes of compounds containing cations of similar size. McCarthy (1971) prepared a number 6f isotypic Sr 2÷ and Eu 2÷ ternary oxides and generally found the unit cells of the Sr 2÷ * Because of covalency differences in M - O and M - F bonds, oxide distances were emphasized. Therefore the radii in Table 1 are m o r e applicable to oxides than fluorides. This subject is treated further in the discussion Effects of covalence. 754 REVISED EFFECTIVE IONIC Table RADII 2. IN HALIDES AND CHALCOGENIDES Referencesfor Tab& 1 The references here and in T a b l e s 4, 5, 6 and 8 are a b b r e v i a t e d according to Codensfor Periodic Titles ( 1 9 6 6 1 . AC*3 v| 68 J | N C A AG, I I1 Tl |NOCA TZ ZAACA 7J IENBA AG*I |v 7L JSSC8 AG,I lvso 4 2 JACS& 69 ACSAA AG*I v 1o J $ $ C 8 AG*I Vl 3 2 ZKKKA . 7 J&CSA 11JSS08 6 9 ACAC8 lO JS$C8 AG, I V l X 7 o JSSC8 6 9 ACACB AG~I VlX| 6 5 ACCRA AG*2 [ V S 0 71JPGSA AGe2 V I 71JPCSA AO*3 lvso 65 ACCRA AL,3 |v 67 ACCRA 68 N J ~ A 7O ACaCA 7 0 NJRNA 7L SPHDA 71 SPNOA 71 AC8C6 12 J $ $ C 8 AL,3 v 6 8 ACDCA 68 A N N I A ALeS v | 71ANNIA 7Z J $ S C 8 72 J$SC8 58 ACCRA 7 2 ACGCA 6 6 JACSA 7 3 &CSC8 6 7 ERKKA 4 &C8CA 4 ZKKKA An*2 vll 72 J|NCA AR*2 VIII r3 J|NCA AN*Z IX 73 J I N C 8 AM*) viii 72 INOCA A~,4 vt 6 7 ADCSA 67 INUC6 AS*5 IV 6 9 ZKKKA 68 CJCHA 63 8APCA 6 9 ACSCA 6 9 AC8C6 68 A N N I A 63 CAHIA 7O ACBCA 7 0 ACDCA 6 9 CHOCA 70 ARR|A 30 |o 393 28B 3 8 2 3 8C CL3 7 1 9 AG FE 0 2 2 6 6 SR AG6 0 4 2 6 3 BA AG6 0 4 364 AG2 CR 0 4 64 3S4 AG3 kS 0 4 23 2261AG2 s O3 L 4 8 4 AG6 "AG2 AG3 AG2 AG2 R02 82 16! 69 222 3 364 25 $116 | 484 NOlO 0 ) 3 $04 P04 CR O4 CR2 0 7 NO o ~ 1 4 8 4 AG6 NOlO 0 3 ) 2 5 $ 1 1 6 AG2 CDZ 0 7 19 180 AG7 N Of| 32 5 4 3 AG F2 32 54) 19 1 8 0 AG7 N 011 AG F2 23 7S ~ NA T | 2 AL5 0 1 2 1968 8O CA AL 8 0 ~ 2 6 1 2 3 0 CA AL6 07 1970 5 4 7 CA12 A L l 4 0 3 3 15 9 0 S CA4 A L 6 o l o ( O H ) 6 |5 995 CA A L 4 07 27 1 8 2 6 8ETA-AL2 0 3 6 6 0 AG & L | I 0 1 7 ~ 7 0 AODCA 7 0 ACSAA 7 0 ]NOCA 6S A¢CRA 7 0 CJCHA 7O ( J C N A 1 | CJCMA 7 0 AR~qlA 71ACDCA 73 80806 81RNHIA 73 CJCHA 66 268C6 6 6 ZAAC4 1| AHRI8 7O 4 0 8 0 6 70 Z~KKA 73 ACSCA 7 ) AC8C6 AS*S v| 7L eaCH8 73 J $ S C 8 7O CJCN6 T ) &C&C8 74 INOC4 74 ACDC6 2 4 1 5 1 8 )NGeFE( AL3 $1 8 o q 5 3 1 0 9 6 ALZ P04 ) 0 H I 3 56 18 • 11 4 :60 5 684 28 ~ 8 9 9 88,~95| ~.~92 1 2 5 ~423 3O 131; 139 129 HA3 AL2 L I 3 F I Z NO AL O3 AG A L L | 0 1 7 NG RL2 0 4 AL2 8 8 3 $ | 6 0 1 8 AL(ACAC)3 A L P 0 4 . 2 N2 0 C5 BE4 B I | 2 - X | ALA 0 2 8 H2 NA A L ) (P 0 * ) Z IO H I 4 AL ( o H I 3 34 3 4 2 7 AM 12 35 35 ~ 8~ &N 0 8 2 ) 6 8 3 AH CLZ 11 2 2 3 3 AN2 (S 0 4 1 3 . 8 H 2 71 3 L30 46 11 25 25 5) 7 26 26 268 55 26 24 9 18 48 48 49 ~ Z7 29 4b ~1 347 347 56 26 132 29 Ze 0 2 2 8 8A AN O3 327 R 188*41 2 1 1 2N2 CU A$2 0 8 9 L ? CU3 AS2 0 8 3 6 1 N G 2 AS2 07 |54A CA H AS 0 4 . 2 H2 0 2 6 5 8 ZA ) H kS 0 4 ) 2 H2 o 18~| NN2 o H 6S 0 4 S b l CA CU AS 0 4 0 H 1 8 8 4 HA2 H AS 0 ~ . 7 HZ o ~5 74 NA2 H &$ 0 4 . 7 H2 o L694 BA N | 2 AS2 0 8 2 0 2 3 NN9 ( 0 H | 9 ( H 2 O ) 2 I A S O3) )AS 0 4 1 2 1 8 8 9 | N H * I 2 , AS 0 4 3711Ll HO 0 2 AS O4 2 2 5 9 CA2 AS O4 CL 7 7 7 CU3 AS O4 |O ~ 3 3 8 q 0 NG2 AS2 0 7 8 8 1 CO) ASZ O8 t 0 3 6 C A ) RS2 08 1 4 8 9 NNT $8 AS 0 1 2 2 1 2 4 H A ) AS 0 4 . 1 2 H 2 0 2 6 1 1 M G ) AS2 0 8 10 77 EA2 8 AS 0 4 ( O H ) k 2 0 8 2 N A 4 . A S 2 OT 133 CA ~ AS O4 ~2 0 |4O SR H 6 8 O4 H2 U I14T ZN4 A$2 0 6 ) O H ) 2 . l H 2 4O3 C6 H RS o 4 332 E03 A$2 0 8 1 4 1 L U AS O4 Z T Z | ~H4 HZ AS O4 49 2 5 1 9 CL FZ AS F 6 6 80 H 8 8 . $ AS) 0 | 6 4 8 3 | 2 4 C08 AS3 u l 6 29 2 6 6 CALCULATED 13 7 8 0 XE AS F | I o A E Z 3O 2 5 0 ~ AS F6 AS F9 b 9 J C $ 1 6 1 9 6 9 1936 X AU F4 7O ZARCA 3 / S 43 L I 3 AU 0 3 o K AU O I , R B TO JC$1A 1 9 7 0 3092 A AU ( N 0 3 ) 4 AU,5 Vl 74 INUCA IS 7 7 5 XEZ AU F I T • *3 III 6 8 NJnNA 1 9 6 1 8 0 C6 AL 8 04 70 8CDCA 2 6 e 0 6 82 O ) t 71SPHCA IS 8 0 2 K 6 8 2 8 0 3 F2 11 6C8C8 21 6 7 2 Z~ 8 4 o l IoI ACSC& ,cDc, FO ZX=KA JCPSA t 4 XRDU8 8 *3 Iv 6 1 AODCA 6 d ACSG4 6 9 CJCNS I I ACOC& ;| At,CA ;U Z~KA ~3 ACC84 7 4 JCPSA 1 | AXN14 73 6HX16 Tl 6C8CA 8 *3 vl T ) ACAC8 86.Z Vl lO Z~8~A t) /EN8& 8Ae4 vii ; | ACSCA T$ AC~C~ 16*g viii 5 8 ZXK~A • 9 JCP$& 70 JCPS& o AU 0 2 26.89 • 8 ~2o3 904 Ll) 27 132 2 4 1 CA 83 O5 )OH) 60 v |899 x 84 0 7 L66L ~ o RL~ 18 g 3 1 4 24 ~4 47 ~t Zl |JZ 16 60 $6 88 2t 29 13! 28~ 869 |70J 2S79 bT7 |Z0Z 241 1133 18V9 15~3 9O9 672 0 2 U3 I I NAB F4 m 8 F4 CU 62 0 4 N N4 8 F 4 CA 8~ O 5 0 H NA 8 l u H ) 4 . Z . Z #N U4 0 7 NG 1 ~ 6 0 T ) 0 ~161 C8 8 $1 U4 o H Z~ S~ U7 ,z Hz o 2 6 6 CALCULDTEO 161 8 6 3 v z O8 2 6 3 8A AOb 0 4 ~7 1263 8A FE2 O4 2 9 2 0 0 ~ 8A2 11 O4 11o 231 c u lu~8~2FIC O O H 1 6 . 4 S l 4 9 2 8 8A s ) ) 2 ; 9 8A CU F 4 NZ 0 7L JCPSA 55 1093 B A N 0 4 71ANNIA 56 7 5 8 8A C OS 7 l ZAACA 3 0 6 I 8A2 CO 0 4 13 ACSCA 29 2 0 0 9 8A2 T l 0 4 DA*¢ Ix T l ZAACA 3 8 6 t BA2 CO O4 13 ACSAA 27 1695 8A TE ( $ 2 0 3 ) 2 , 2 HZ O 21 1653 B A T E ( 5 2 0 3 ) 2 . 3 H2 0 73 ACSAA 8Ae2 x 1o ZKKKA 131 let 8A3 I V 0 4 ) 2 70 AC8CA 26 105 8A3 $ 1 4 N86 0 2 6 90 24 8A p z 0 6 6 7 BUFCA 8A*~ xl 71 AGDCA 2 7 1263 BA FEZ 0 4 BA*2 X l l 70 ACDCA 26 t 0 2 8A5 TA4 0 1 5 72 CSCNC l I BA T I 6 0 1 3 71NRSUA 6 7 2 5 8A CA FE4 0 8 69 CN0CA 2 6 8 0 1694 BA N I 2 AS2 0 8 ~5 AC~CA )I .596 K2 BA CU ( N O216 8 8 * ~ 111 6 9 ACOCA 2 5 1647 SR 8E3 0 4 oo AC8CA 20 2 9 5 C A t 2 8 E 1 7 O29 8E*Z xv bZ SPHCA 6 733 NA BE p 0 4 08 ACSCA 24 6 7 2 LA2 BE2 0S 60 ACDCA 24 8 0 7 CS BE F 3 6 9 AC~CA 2 5 1647 SA 8E3 0 4 71SFNCA IS 9 9 9 FE3 8E $ 1 3 09 ( F I O H ) 2 72 SPHCA 16 1021 8E2 S l U4 72 AC8CA 2 8 1899 AL2 BE3 S l 6 0 r e 73 ACBC~ 2 2 9 2 9 7 6 NA3 8E 7 H I 0 F 4 5 $ 9 ACCRA IZ 6 3 4 BE ACETATE 6 7 ZKKKA 128 4 2 3 c s 8E4 8 1 1 2 - X ) AL4 0 2 8 H2 T4 ACDC6 )0 3 9 6 NA6 ( $ 1 1 6 A L 2 t 8 E ( O H ) 2 O391 1 , 5 H2 0 74 "DCDCA 30 2 4 3 4 L I 2 BE I 04 7~ ANMIA 59 1 2 6 7 CA 8 8 2 P2 0 8 8[*S V 6 9 35C0A 7 1797 8 1 2 N 0 6 7O ACSAA 24 3 8 6 ~ ( 2 03 ALPHA 81"3 Vl TO ACSAA 2" 38 4 8 1 2 0 3 ALPHA ~1JFCSA 3 2 131 5 8 1 F E 0 3 BI*) VIII 72 NABUA 7 102581TITANAYES BI*~ v| R3 VS V (8A2 LA B I 061 6K'4 vl 6T |NUCA 3 327 A (8K.41 8 8 * ~ i v SQ 6 9 J C S | A 196e 1936 K aR F4 8R.5 Ill 6 9 ACAC8 25 621SN (GR 0 3 1 3 o q H 2 o 6 7 ACSAA 21 2 6 3 4 HG OR 0 3 8R.7 Iv 71JC$1A 1971 1 8 5 7 0 R ( * 7 1 - O C.4 III 65 ACCAA 18 6 8 9 CA C O3 7L JNSAA 75A 27 CA C 0 3 73 A N N I A 58 1oa9 NO c 0 3 67 PDLAA •z t 2 5 NN C 0 3 75 AC8CA 31 8 9 0 NA2 C 0 3 . H 2 o CA*2 V| 6 8 NJNAA 1 9 6 8 8 0 CA AL 8 0 4 6 9 ACSCA 2 5 1933 CA NA ( H I p 0 2 ) ) $ 7 JCPSA 26 563 CA ( o H I 2 65 ACCRA 18 6 8 9 CA C o ) CA*2 Vll T l CJCHA 4 9 1 o 3 6 CA3 aSZ 0 8 71AE80A 2 7 2 3 1 1 CA2 AL FE 0 5 73 NR8UA 8 5 9 3 CA C~ FS 6 9 ACSCA 2 8 1534 CAIO | p 0 4 ) 6 IO H I 2 CA*Z VIII 68 INOCA 1345 CA2 P2 0 7 14 CJCNA 5 I155 GALe NG2 H2 ( p O4"114 CA-Z IX • 7 | JNDAA 75 27 CA C o ) 6 9 ACSC4 2 5 1 5 3 4 CA|O ) p 0 4 ) 6 (O H ) 2 CA*Z x 6 9 ACSCA 25 9 5 5 CA 82 0 4 I l l CA*2 x[I 69 AC8C6 25 9 6 5 CA 82 0 4 I v 74 AXNIA 89 41 CA AL3 ( 0 H ) 6 I P 0 3 1 O t / 2 IO H 1 1 1 2 1 1 2 74 JACSA 9 6 6 6 0 6 X2 CA CU I N 0 2 ) 6 C0.2 IV ~9 ACCRA 12 l o 4 9 CO I N 2 04 11Z4ACA 382 2 T o 8 2 C0Z o~ co*z v 6 9 CJCHA 47 3409 co| pz 07 70 ZXK~A 132 1 3 2 C03 A S | 0 8 C0*Z vx 09 CJCHA 4 7 3 4 0 9 CO2 P2 07 r o ZRKK& 13Z 332 C03 AS2 0 8 6 6 SPHOA 11 11 c o w 0 4 6 7 HCACA SO 2 0 2 3 C0Z HN3 0 8 14 J C S I A 1 9 7 4 6 1 4 C0 C4 H6 0 6 74 ACSC& JO 188o C02 G4 H12 0 1 2 C0.2 VII 74 4CS6& 2#A 119 0 o D i e H2 c o 0 ) 2 . 3 l l Z HZ 0 C0 DeC H2 c o u ) z . 3 Ha O 7~ J C S l A 197~ t q Z z c o c ~ H 5 0 S co*z vlxx . 98 9 0 3 CO2 NSZ 0 7 AC8CA 25 1806 00 (N 03)2.4 D2 u 6 7 6 CO C4 H6 0 6 t 4 J C S I ~ 1976 C E * 3 vlll 74 ZADC6 4 0 3 I R) v $ v ICE F31 74 J C S I 6 1974 1 1 6 5 C41 H 2 4 CE F I 2 N De 84 CE*3 IX 67 SPH~A lZ 2 1 4 CE e s t O5 I R3 V$ V ICE F $ ) T4 ZADCA 4 0 3 cE*3 x 6O A N N I A 45 I CE~ ME ME2 7 1 2 5 1 4 0 2 2 CE,4 vl 72 ACOCA 28 9 5 6 8R CE o ) v 131R )CE4,) 73 JS$C8 CE.4 VIII 8 $3 1~ N 4 1 2 CE F6 JC$1A 1174 2021Ni6 CE u l O 0 3 6 H 2 . 3 0 H 2 o 74 J$TCA l~ 39t CEIS 04)2 F4 ACSAA 2 8 1079 A - CE t A C A C ) 4 C t * 4 XXX 68 JSCSA 90 3 5 8 9 I N H 4 ) 2 H6 ICE NOt2 0 4 2 1 . 1 2 H2 0 C F * 3 VX F4 J I N C A 36 2 0 2 3 R3 VS V ICF2 15 0 4 ) 3 ) C L * 5 111 T3 NASUA 8 791 8 8 CL 0 3 CL*/ Iv r z ACDCA 28 039 TMPO CL U4 12 ZK~XA 0~ 65 X CC 0 4 6O ACL~A 13 e s 5 N o z CL 0 4 , n CL OA, Hct 0 4 . N 2 O , C l CL 0 4 . 3 H2 O s q JPCNA 6) ZTe H CL O 4 . H 2 0 ~8 JRCSA 0 0 8 0 / 5 C6 HD.AG CL 0 4 $7 P l S A A 56 134 N H4 CL 04 ST P l S A A ~6 143 K CL 0 4 6 2 ACCJ~R 15 1 2 0 1 N N4 CL O4 71 J C S I A 1971 1 3 t l c u ) c l o H9 N ) ) 2 COL 0 4 ) 2 7O AC~CA 2 6 1928 Ha . s CL 0 4 11 AC8C6 zt 8 9 8 H CL 0 4 . 2 112 H2 o 13 I C " D A 1 4 1 7 ¢G N I 2 - T R I E N - C U CL 0 4 11A¢DCA ZT 8 9 8 x CL 0 4 , Z I l l ,2 0 12 7t 62 bQ 13 NRSUA 7 1281CL(*7) -0 J C S I A 1971 1 8 5 7 C L ( * 7 ) -o ACCRA 15 I s N3 o CL 0 4 1 - 8 0 C I ACDCA 25 ~875 N H3 o H CL 0 4 ACSAA 2 7 2 3 0 9 )PaR 1o H 1 4 1 3 C 0 3 (CL 0 4 1 1 0 . o H2 o 73 ACSAA 273523 CU i t 3 H4 N I ) * (CL O412 CN,~ vi 67 )NUCA ) )27 R ICE*4) cu*z I V 69 ZAACA 369 306 C0 V2 U4 C0,2 v 12 ACBCA 2 8 2 8 0 3 C02 PZ 0 7 ALPHA C0,2 v! 68 ZAACA 3 5 8 125 CO SE 0 6 08 ZKKKA 120 2 9 9 CO GE 0 3 70 CJCHA 48 881 C03 A$2 0 8 70 JCPSA 5 ) 3 2 / 9 BA C0 F4 10 P E P l A 3 | 6 1 C02 SI OA 7 J AC~CA 2 9 2 ) 0 4 CO3 V2 O8 T l HCACA 54 1621 CO3 (O N ) 2 ( S 0 4 | 2 ° 2 H2 0 REF I C02 $ ! 0 4 72 ACECA 28 2083 COl pz 07 70 INOCA 9 l S I CO ( O N P A ) 3 (CL 0 4 1 2 73 ACBCA 2 9 2 7 4 1 CO S I F 6 . b H2 0 74 A N N I A 59 4 7 5 C02 $ | 0 4 T4 JCHL8 4 55 C | 6 H 1 8 CO 0 6 CO*Z V ) I I 6 6 INOCA S 1208 (A$(C6 HSIRI2(CO(N O3J~) co,) Vl LS. 6 8 CCJDA 1 9 6 8 871 c0 (N 0313 O80JCHA 4 6 3 4 1 2 C03 0 4 6 6 JACSA 8 8 2 9 5 1 C0 (CS H7 O213 74 ACUCA 30 8 2 2 C0 1C5 H7 0 2 3 3 69 JACSA e l 6 8 0 1 I N H 4 1 6 ( H 4 C02 N 0 1 0 O381 • , 7 H2 o 74 ZAACA 4 0 8 97 K C02 0 4 C0"4 IV 71ZAACA 306 I 8A2 CO 0 4 73 ZAAOA 398 54 L l 8 G0 0 6 7 4 ZAACA 4 0 8 75 C52 CO 0 3 74 ZAACA 4 0 9 lsz 86 co2 o7 C0.4 v) HS 6 7 STGBA 3 I 8 3 VS V ( F L U O R I D E S ) 14 ZAACA 4 0 8 97 K C02 0 4 CR*2 vl LS 7L ANCPA 6 411A2 CR 0 6 6 9 ACDGA 25 9 2 5 8 VS o ELECTRONS CA*3 vl 6 9 MDUUA 4 6 2 | NA3 CR F6 7O INOCA 4• a Z Z 8 HA3 )CR NO 006HOZ4 M 6 3 . 8 , 2 0 1o ACSAA 2 3 6 2 7 ~A2 CA3 0 8 73 NROUA 8 5 9 3 CA CR FS 6 5 ACCRA 19 1 3 1 C R | C ~ H7 0 2 1 3 CR*4 IV 14 ZAACA 4 0 7 129 BA2 CR 0 4 CR*4 Vl 72 NRBUA ? 1 5 7 CR o z CR*5 Vl 67 SEGOA 3 I A3 v s v ) F L O O R ) D E S ) CR*6 IV 6 8 CJCHA 96 9 3 5 K2 CR2 O7 70 ACGCA 26 2 2 2 CR 0 3 6 9 JC$1A 7 9 8 9 1 8 5 7 ( N H R ) 2 CR 0 4 h 9 ACAC8 2 5 $|16 AG~ CR2 0 7 70 5PHDA 15 5 3 0 K2 CR4 0 1 3 to ANNIA 55 7 8 4 P82 CR2 0 5 7 0 ACSAA 2 4 3 6 2 7 N2 CR3 0 8 0 H 71 $FHCO 15 8 2 0 NA2 CR2 0 7 . 2 H2 0 71SPHCA 15 8 2 6 L I 2 CR2 0 7 . 2 H2 o 73 AC8CA 29 BqO NA2 CR2 0 7 ALPHA 71ACSAA 2S 4 4 RB2 CR2 0 7 7 0 CJCHA 48 5 3 7 8 8 2 CR2 0 7 71ACSAA 2S 35 R82 CRZ 0 7 71JSSC8 3 3 6 4 A02 CR 0 4 72 ACeCA Z8 2 8 4 5 82 CR 0 4 73 ACSAA Z7 1 7 7 ZR4 CO H | 6 CCR O ~ ) S . H Z O 73 ACSCA 2 e 21~l R82 CR4 013 •73 6COCA 29 2 9 6 3 NA2 CA 0 4 . 4 H2 0 71JCSIA letl 1 8 5 7 ( N H R I 2 CR 0 4 73 NRDUA 8 271 K2 CA2 O l C R * 6 vl 74 AMMIA 59 1 1 0 0 P86 CR CL6 X6 V2 C$*l vlll 0 9 SPHCA 13 9 3 0 CS2 BE F4 CS*l x 6 9 INOCA 8 1 6 6 5 CS4 M03 F I O 6 9 $PHCA 13 9 3 0 C$2 BE F4 cs*l xl 6 9 INOCA 8 1 6 6 5 C$4 NG3 F I O C$.1 x11 67 ACCRA 23 8 6 5 C$ U F 6 6 8 ACSAA 2 2 2 7 9 3 CS CO CL3 71AC8CA 27 2~S C$ U6 F 2 5 CU*| II b 9 ZKKKA 129 2 5 9 CU LA 0 2 70 ZAACA 3 7 9 1 1 3 SR CU2 O2 CU*| Iv 49 ACCRA 2 158 c u CL3 Cu*l vl 70 NRBUA S 2 0 7 CU TA 0 3 cu*a Iv 57 ACCRA 10 5 5 4 c u CR2 0 4 71ACIEA 1o 4 1 3 SR CU 8 4 , CA CU F4 CU*2 IV $0 O7 ZK~KA 124 9 1 Z N 2 CU 6 8 2 O8 68 ACBCA 24 888 cuz IN2 05 t l ACBGA 27 6 7 7 CU 02 0 4 6 5 JCPSA 4 3 3 9 5 9 CU ( 0 6 H S I C H 3 ) 2 C ) O212 6 6 INOCA $ 5 1 7 CU 1 0 | 0 H9 0 2 1 2 61JCS~* 1967 3 0 9 CU ( 0 4 C l 2 H I 8 ) 6 6 PRLAA 2 8 9 161 C14 HLO 0 4 CU 70 ACSCA 26 8 cu o cu.z v 6 9 ACSAA 23 221CU) W 0 6 ~8 C a ) H A 46 9 1 7 CU3 AS2 O8 6 8 JCPSA 40 2 6 1 9 CU NO 0 4 cu*z vI :I .ACCDA . . . . . . .|.6. . . |.z.4. .c.u.5 '68 ;o 68 68 JCPSA AC8CA CJCHA J&CSA 70 )NOCA t 3 ACBCA CU*3 Vl 12 MRBUA DV*Z v ) UNPUI DY*2 V l l UNPUI OY*Z V I I I uNPul or,3 vl 6 3 PHSSA 0Y'3 VII I t JCNLB oy.1 viii I ~ .$$COA ...... ov.J ix ) p o 4 3 2 ~o , 1 4 4 8 2 6 1 9 CU NO 0 4 2 6 10Z0 CU i o ~ ~6 60S CU2 P2 O7 90 5621 CU(((C H3)2 N)2 I P l 0 1 2 O111 ; e l 0 4 1 2 9 is| cu )O~FA)3 (eL 04)2 2 9 1 7 4 3 CU V 2 0 b 7 9 1 3 LA GU 0 3 OY 12 Of Ct2* 0Y 8R2 ov eL2 3 K446 0 ¥ 2 o ) | 83 OYITHO)3oH2 0 1 | 7 1 ~ .o.r. ). . . . .FE3 ... all R. D. SHANNON Table 74 2AACA ER*3 Vl 7~ ACbCA ER*3 VII TO SPHCA 72 JCMLB ER+~ V I I I 6 8 CHPL8 ?0 [NOCA 7O SSCOA 7L ACSAA 403 I 26 484 13 Z 36 ER2 GE2 0 7 1 9 7 ER8 U i T H D ) I O ~4 ZAACA 4O3 2 ER2 S12 OT 10 H ) 1 2 2 4 7 ER ~ 0 4 . ER V 0 4 9 2AO0 ER I C 2 0 4 ) I H C2 0 4 ) . 3 H 2 8 1 7 4 5 ER3 F E 5 0 L 2 28 372 E~ | H U C H2 G 0 O 8 3 . 2 H 2 3 6 2 EK I C 2 H3 S 0 4 ) 3 . 9 H 2 I R3 V$ V IER F31 201 oA+~ I V 16 ACRC~ T5 AC~CA GA.) V l 14 A T R I A GD*3 V I I 70 &CBCA ?2 ACSCA T2 SPHC~ O9 [VNM& T2 JSSCB GO*J V I I I IA SPHCA l Z SPHCA 74 ZAACA ~ 0 ~ 3 ZX 72 SPHE& 6 9 IVNNA 7~ ZAACA OE*4 I V 68 ZKKKA 69 $ C I E A 69 Z~KKA 7O JS$CB Zl sP-c* 70 ACSAA 6 7 ACSAA 7~ NOCNe I1 " 0 C ~ 6 72 SPHCA 12 ROCk5 GE*4 v i 10 SSCO~ I0 J$$C8 TA ,OCM8 TA AC~CA 12 ANN1& 12 2KKKA TZ ~OCM8 .,A I ............ L! 0 EU3 O4 EU F Z , EU 8RZ 7~ EU CL2 EU F2 2 1 8 EU2 SI 6,,cc. EU4 AL2 o g L 1 2 EU5 8 8 l o g 4 EU3 FE2 GA3 0 1 2 I R3 VS V (EU ~38 2 5 2 7 EU2 I C 3 H2 0 4 1 3 . e H 2 0 20 (cont.) 8 6 9 HG NO 0 4 2049 1745 437 1 | R3 V$ V I H U F J ) 2 6 1 3 HOICZ H5 S 0 6 ) 3 . 9 H 2 409 IS 24 24 llbE BA FE S14 0 1 0 139g 3O6 452 |29& ( N A , K ) 2 FE4 S [ A 2 FE V2 O4 FE2 TI 0 4 FE2 MO 04 0 030.H2 0 V25 R VS A I F E S21 4 3 0 FE AL~ IP O412 IO H J 2 l 0 .2H2 0 tgO ~E S O4 g 9 9 FE3 BE S I 3 0 9 [ F I O H I 2 7 7 5 FE ( N H 4 ) 2 ( $ 0 4 ) 2 , 6 H 2 0 290 LIFE P O4 4 8 & F~2 SA 0 4 79A GARNE~$ 333 FE3 A L 2 S I 3 2 6 6 CALCULATEO 1469 1745 A263 T2S 36A6 832 I Z469 1745 335 I 6315 3616 239 440 0L2 CA2 FE2 OS M3 FE5 0 1 2 BA FE2 0 4 BA CA FE4 0 8 CA2 FE2 05 6A FE2 0 4 FE V 0 4 CAZ FEZ O5 ~3 FE5 0 1 2 K FE F4 FE v 0 4 B I FE O3 CA2 F E 2 0 S FE lOS H7 0213 FE I C 7 H5 0 2 1 3 33L ESTIMATED 3 3 1 R3 VS V I P E R O V S K I T E S I R3 VS V I S ~ Fe O3) *3 K2 FE 0 4 R3 VS v (K2 FE 0 4 ) 6t6 L | 5 GA 0 4 56O S~ OAZ S l Z 08 3O 1364 ItS HAl Ob O& 26 4 8 4 GDZ S I 2 0 7 28 6 0 GO2 NO3 O12 16 7 9 0 G O 2 0 E Z 07 5 1823 G O g . 3 3 S I 6 0 2 6 S 266 0 0 9 . 3 3 $ 1 b 0 2 6 1~ 16 4O3 9 2 6 NA GO S ] 0 4 79O ~ 0 2 GE2 O? A R3 V$ V IO0 F ) | 16 7 9 0 GO2 GEZ QT 5 IR23 GD9.33 S]6 026 4O3 A R3 VS V IO0 F 3 ) t26 165 129 Z 18 24 2A A02 IOZ t7 103 299 586 427 612 ~a~ 1287 12B! 964 I245 244 1560 CO 0E 0 8 AN2 GE 0 4 ~N3 FEZ GE3 OAZ ~ 0 2 8 G E| O 0 4 8 ~ sm GE o~ NA4 $N2 GE4 0 1 2 I 0 H I 4 NAB SN4 GEIO 0 3 0 (O H I 4 NAZ 0£ O3 K 2 0 E ~ O9 CO GE O3 GE5 0 ( P 0 4 1 6 1 $ 5 7 CA2 GE O4 2 662 . G 2 8 GEtO O48 Ao2 I Z 4 S K 2 0 E 4 0 9 2T 2 1 3 3 OE 02 ~1 62 MN2 GE 0 4 OELT& 186 38T Ge I O H I P 04 103 AS60 GES 0 I P 0 4 ) 6 + 13 2 3 5 0 N H~ 750 L| | 841LI 1 1015 CEII 794 C i I I 7 2 9 N H4 I 03 O] 03 0314 0314.H2 I 03 ZT~ ~ ~ o2 ~ ~C$AA ZJ 3341 I0 ,42 14 AC>AA 2T 3467 . P ~ ( O , 1 8 .F*4 VIII TJ &CSAA 27 Z * 5 5 NF ( 0 H I 2 .0,1 vl ? l CCJO& | 9 1 | 4 6 6 NO2 F2 2 5 5 6 N H4 I 03 1782 NA I 0 4 308 A I 04 1 8 5 7 II*TI-U 7o~.s. ,'/6 INOCA ~9 ZKKKA S 04 0 0 97 ~82 IN4 07 2 8 0 SR2 I N Z 0 3 9 7 R82 I N 4 0 7 t437 IN O H S 04.lHZ 3 e 8 CUE I N Z OS 1662 IN 0 0 H 3583 , G 2 NAZ $ ] 6 2667 K~ NG 84 OAR A966 ~G) P2 0 8 A42 MG 84 0 7 NG3 P2 O8 RG2 P2 07 A l S q . G 2 P2 07 36A ~G2 A$2 OT 1419 , G , H4 P O* o41 S 04*~Z 0 IC~ 0 4 1 4 . , Z 0 012 AC6CA 30 1882 NA I N S l Z 0 6 74 SPHOA 18 7 6 t I N Z GE2 07 Vl 7A J 5 $ C 8 3 1 7 4 SR ZR 0 3 IR+S V I 74 NROUA 9 1177 R3 VS V ICO2 I R 2 071 K*I IV 68 ZAACA 3SR 2 4 1 K AG O RE~ 2 K2 0 K*Z VI SA ZAACA 2 6 4 144 K 58 F6 6 8 SPHOA 12 1095 K Y N02 0 8 09 CCJDA II 6 0 6 K2 ZR2 O5 b 9 ACUGA 2 5 1919 ~ U2 F9 K*L vii ~e CJCHA 46 9 3 5 ~2 ¢R2 0 7 69 JCSIA 19~9 8 4 q KZ NO 0 4 TA S~COA S 3 3 8 ~ FE F4 K*I Vlll ~0 ZKKKA 74 3O6 K H2 P 0 4 62 ZKKKA |AT 4A1K2 TI6 013 37 ZKKKA 98 2 6 6 K H2 I H 3 O) 85 0 1 0 7A INUCA 7 8 7 3 K H C2 0 4 6 8 CJCHA 46 9 3 5 K2 CR2 O7 70 J C S I A 1 9 7 0 3 0 9 2 K AU I N 0 3 ) 4 6 5 ACCRA 19 6 2 9 K4 H2 12 0 1 0 . 8 H 2 0 K*| IX 70 ZKKKA 132 27 K A . 6 N A S . 5 CAO.3 A L T . 3 L18*5 032 6 9 ~CBCA 25 6 0 0 K CE F4 6 9 ACSCA 25 1 9 1 9 K U2 F9 K*A X 73 CJCHA $1 2 6 1 3 K AL P2 0 7 K +I XII 6 8 SPHCA 13 4 2 0 K Y ~2 08 ? l INOCA 10 1264 K2 P8 CO I N 0 2 1 6 67 I~0CA 5 5 1 4 K2 BA CO I N U 2 8 6 74 IACSA 9 6 6 6 0 6 K2 CA CO I N 0 2 ) 6 75 ACOEA 3A $ 9 6 K2 8A CU I N 0 2 1 6 57 PASAA 56 643 K CL 0 ~ LA*3 Vl 6 9 ZKKKA 129 2 ~ 9 CU LA 02 T3 NRUUA 8 1 2 6 9 ~ 3 V$ V I ~ E 2 ~ 3 0 A 2 1 LA+3 V I I ! ?4 A N N I A 59 1277 LA4 ~G2 T I 3 S [ 4 0 2 2 73 ACRCA 2 9 2 0 7 4 LA2 H03 U I 2 6 8 INOCk 7 2 2 9 5 LA ( C 5 H7 0 2 ) 3 I H Z 0 4 2 74 ZAACA +03 A R3 VS V ( L A F31 7~ SPHCA L8 67S LA2 SR3 (B 0 3 1 4 LA*3 IX 71NRBUA 6 2 3 LA FE 0 3 ?~ Z ~ C A ~O~ A ~ ) VS V ( L ~ ~31 74 A~IA 59 12T7 LA~ NG2 T13 S I 4 0 2 2 LI+A IV 3V ZKKKA A02 119 L I O HoHZ O TO 2AACA 3 7 9 | 5 7 L I Z CU 02 70 INOCA 9 1 0 9 6 Y8 L [ F4 71AMNIA 56 18 NA3 AL2 L l 3 F 1 2 71ACSCA 27 0 6 6 L 1 5 OA O4 T3 JSSCB 6 538 L I 3 V O4 73 ACRCA 2 9 2&Z$ L I {N~ HSI 8E F4 T ) ACBCA 2 9 ~ 6 2 8 L [ N H3 0 H $ 04 6~ ACCRA 17 7 8 3 L I 2 C2 0 4 14 ACSCA 30 2 4 h 6 L I Z 8E Sl 0 4 LI+L V| &8 ACBCA 24 2 2 3 L | 3 AL F6 6 9 2AACA )TA 3 0 6 L 1 2 ZR O3 70 ZKKKA 132 I 1 8 L I 2 AL2 S [ 3 0 l O TA ~RRUA 6 ~ U Z ~0 F6 6~ A¢C~A 19 ~ 0 1 L I C6 07 H7 74 A¢IEA 66 819 LI N8 P 0204 68 CZ~YA 66 29O Ll Fe ?l A¢SA6 2~ 3387 LI N ~ O8 73 IJCHA ~Z 26~ LI V OJ T3 ACBCA 29 2 2 9 4 L I 2 ZR F6 CU+3 V l 7O ZAACA 3T7 70 C~ LU2 O4 ?z J*CC* 4 2 ~ ~ u e o~ LU*~ VIA! 74 ZAACA *03 | R3 VS V ( L U F31 LU+3 IX 7~ ZAACA ~ 0 3 A R~ VS v ( L U F31 ~G*2 I v 72 AC§C~ 28 2 6 7 KZ NGS $ I 1 2 0 3 0 AC~CA 2 ~4 ACUC6 30 ~0+2 V 6~ ~CSAA ZZ &6 , J N N A 1966 UNPU$ UNPU3 NO*2 V l 65 CJCH& ~) 68 UAPCA 11 TO ACeCA 26 ,3 7 2 7 5 6 3 V5 V 1~4 . F H236 0 2S35"HOIN2 014 IH C 0313.2H2 83L IN OIZIHOIN 03)51 19 6 2 9 K4 2 0t0.8H2 59 2 0 3 6 I N H 4 1 Z H ) [ 0 6 409 393 74 T| 73 74 K HO BE F6 H 0 3 FE5 0 1 2 H0 Pb 0 1 4 R3 VS V IHO F 3 I IR'4 A R3 VS V I E U F 3 | 2 8 2 7 EU2 ( C 3 H2 0 4 ) 3 . 8 H 2 33~7 EU TRISGLYCOLATE 2T 36 2 73 ACBCA 29 H0*J VIII T~ ACBCA 30 TO SSCOA 8 72 8UFCA 9S 74 ZAACA 4 0 3 HO+3 I x 14 ZAACA 4 0 3 7 4 ACOCA 30 H0+3 X T4 INOCA 13 75 CJEHA S3 1.5 Ill 71JCPSA 54 6 6 ACCRA 20 6 6 ACCRA 21 58 ACGRA 9 58 ACCRA It 4 3 RTCPB 6Z I+5 Vl 7 t JCPSA 54 1+7 IV ?0 RCBC~ 26 2 6 ZEPYA 3g 71 J C S I A A971 I*7 VI 6 5 ACCRA 37 JACSA IN.3 IV T4 ZAACA 73 ZAACA IN*3 VI 74 ZAACA ~ t ACSAA 6 0 ACOCA 70 ACSAA 04 EU4 AL2 0 9 L | EU3 0 4 L I 2 EU5 08 201 8 ....... 0 201CI EU3 O4 It04 EU 12 L I 2 EUS 0 8 7O SUFCA 93 71SPHCA |5 6 ? ACCRA 22 6 8 GIWYA 68 14 A ~ N [ A 59 FE*2 rill TA AMMIA $6 71ZKK~A 134 T3 ACAC8 29 FE+J AV H$ TO ACECA 26 70 SSCOA 8 ?1ACRCA 27 I I MREUA 6 71AESAA 2S 73 ACBCA 29 FE+3 v TA JS$CB ~ FE*3 vI H$ TO ACSCA 26 70 SSCOA 6 71SSCOA 9 ?L JS$CB ~ TL JPCSA 32 11ACSAA 25 67 ACCRA 23 6 9 CCJO~ 1 9 6 9 FE*) VIII T3 JSSCB 8 FE*4 Vl 73 JSSCB 8 FE+o I V z~ JSSCB 0 I R3 VS V (eR F31 I97 ER8 0 I T H D ) I O I 0 N ) 1 2 72 JGHL8 ER.3 IX 5 9 ZKKKA 112 ?4 ZAACA 4O3 EU+2 V l 7O ZAACA 374 EU+2 V I I 70 2AACA 3 7 4 6 9 ACRCA 25 7 3 REF 3 EU*2 VIII UNPUt EU+2 I x 73 RVCMA |0 UNPUl EU+Z x ? l NATMA S8 EU+3 V l 68 REF 4 7 0 ZAACA 374 73 REF 3 EU÷3 V I I 68 REF 4 13 REF 3 EU+S V I I I 65 JCP$A 48 ~ ZAACA 4O3 3 ACSAA 27 EU+3 [ X 74 ZAAC~ 4O3 73 ACSAA 27 71ACSAA 25 F E * Z I V SQ H$ 74 AMHIA 59 FE*Z IV HS 69 $C]EA L&6 6 9 ZAACA 3 6 9 TI JUPSA 31 12 JUPSA 33 FE*Z VI LS 69 ACRCA 28 FE+2 V I HS &9 NJMMA 1 9 6 9 • 6 JCPSA ~P.~ Iv TS J 5 5 C 8 NF.~ Vll R3 VS V |OY F 3 ) 2 755 8 A665 E$4 H03 FAO IZ9 6~ NG S l U3 698P.C, lI 93,,.. 10 J 5 5 C 8 ~12 . G 2 e I0 O48 6 ~ .NL.O 196~ i v 6 . ~ AL 6 o , 70 BSC++ 1970 + 2 4 3 "G $ 0 4 . . Z 0 71 l c e c l z? 813 .~ =E o 6 bB &CSAA 22 A466 MG$ P2 08 ro 6 k F A C~ MO Sl O4 0 AGSCA ANM|A ANMIA CJCNR 10 INOCA 72 C J C H i 7~ ACBCA NG*Z V I I I 73 AGRC8 MN*Z I V HS 70 ANNIA 6 9 ZAA¢A F I AGBCA 6 9 PMSSA 13 ACACB NN*~ V HS 6e ANNIA 74 MPMTA ~N*Z VI LS 0 9 ACBCA MN*~ Vl HS 6 9 SGIEA 6 q JCPSA 70 ZKK~A 6 g ANMIA 70 N J ~ I A 6 5 ACCRA 72 A N N I A 6 7 PRLAA 67 HCACA MN*2 V I I 72 AMNIA MN*Z V I A l 6 9 ZKKKA 71AMM|A 73 SSCOA 74 JCPS6 NN*J V! HS 0 7 ACSAA b 7 ZKKKA b8 ACSCA 6 9 JCPSA 6 3 PHSSA 6 8 BUFCA 7A JS$C8 7J JSSC8 7~ A N N I A 6 8 ACBCA * INOCA 4 INOCA NN*~ IV 7S JSSC8 NN+~ V l 73 JS$CB 6 9 INOCA 6 3 CZYPA 6 7 HCACA .N*6 IV 12 ACOCA M~*7 I v 6 8 ACOCA MO+3 V I 6 9 ACBCA 6 9 INOCA .0.~ vl 7A MRUUA MO+~ IV 7 4 INOCA ~O.S Vl 7 t INOCA ~ 68 JCPSA 6 8 SPHDA 69 JCS|A 72 ACUCA 6 9 JCPSA 71 SPH~A ?A SPHCA 71JCPSA 73 ACBCA 71JCSIA NO*6 V 67 CCJOA 08 J C S I A NO+6 VI 68 JCSIA 70 JSSCB 70 INOCA r o ACSAA 6 6 ACSAA TO CCJOA 6~ INOCA 73 ACRCA 74 ACECA Iv REF 6 N*5 Ill REF 6 JO 86 $8 $2 q SO 29 29 2 4 9 1 M G 2 V2 0 1 | 5 8 3 NG 1 8 6 O f I 0 H I 6 1 * Z H | 1 0 Z 9 MG C OS 11S5 CA L l ~G2 HZ I P 0 4 1 1 6 I S I ~G I O N P ~ 1 3 (CA 0 4 1 2 3 6 1 9 NG Y2 U6 2 6 1 1 M G 3 AS2 0 8 266 CALGULAIIO NN? S | AS U | 2 Iq~ VZ 0 4 NN CO CA 0 4 MN ¢R2 0 4 GALGULATEO 55 1 4 8 9 369 306 2T 1 0 4 6 J2 Kql 29 266 53 21 28 U 1 8 6 1 M N 2 0 H AS 04 2 6 6 NN2 AS OA OH 9 2 8 R VS 0 £LECTMONS 168 SR6 ~ Z GE U6 51 4 9 2 8 BA MN F 4 l~Z INNS tO N l z $ 1 2 0 8 5 4 | 3 6 2 NN eE2 | P 0 4 l Z I O H I 2 . S H 2 0 113 1MN? ~A|2 IS 0~)1$.18H2 0 19 8 8 ~ MN S O~ ST 6 2 1 M N 2 GE 04 9~ i ~ 5 NN C 03 )020)) MN) 0 8 S? 621MN2 GE O~ 229 427 56 791 12 L09 6~ 1899 ~ N ) FE2 GE$ 0 1 2 GARNETS NN3 AL2 GE3 0 1 2 MN U4 0 7 Z& 124 24 50 3 9~ 3 MNZ 0 3 NNZ 0 3 jl~ 0 0 H I N H 4 ) 2 RN F5 f'~Z 03 TO NN 0 8 , PR n N O ) , N u x N O ) LA JCN 03, RN3 04, L A . 9 S CA.o5 #N 0 3 NA MN? 0 1 2 NGZ ~N e o s NA4 MN~ TLS OAR ~N I t 7 H5 0 Z 1 3 , 1 1 4 C6 HS CH$ ~N IACACi3 ZO?| 428 1233 1066 K.46 339 238 6 16 39 9as 2 4 11A4 13 IRSA 13 1 8 6 4 L3 2 7 5 R3 V$ V IM4 NN O ~ l 8 23k 8 33S 13 39e SO 2 0 2 3 8 6 NN O3 NIL2 NN NBL2 0 3 8 . S O N 2 NAT H4 MN I I 0 6 I S * I T H 2 NN5 GO, c o 2 MN) 0 5 0 2 ~ 1 0 5 3 AG NN 0 4 25 4 0 0 KJ NO CL~ 8 2 6 9 4 K8 NO F6 6 5 5 5 L 1 2 MO F 6 13 2 7 1 5 t0 R3 VS V ¢AE N 0 0 * l 9 2 2 8A2 NO NO 0 6 48 12 1969 28 50 18 15 55 29 1971 2 6 t 9 CU N0 O~ LOgS K Y N 0 2 0 8 8 4 9 K2 1~3 0 4 6 0 GU2 NO) OA2 8 6 N02 NO3 0 1 2 611LI3 FE NO3 0 1 2 8 2 9 K AL N02 0 8 . K FE ROE 0 8 1093 CA N0 0 ~ , SR NO 0 * 2 0 7 4 LA2 NO) O12 1 8 5 7 NO(*63 - O 1967 1968 3 7 4 ~2 NO3 0 1 0 1 3 9 8 KZ X0$ O10 19&8 1 9 24 20 1970 13V8 K2 M03 0ZO kS& AG6 M010 0 3 3 2 2 2 8 NA3 ICR MO 0 6 0 2 ~ H b I * R H 2 3711Cl ~ 0 0 2 AS O~ 2 6 9 8 NO F 6 IGASI SO NO 0 3 ( H 2 0 ) 2 1603 K I R 0 O2 C2 O4I H2 0 1 2 O 29 8 6 9 HG NO 0 4 30 11V5 NO 03VHZ O N-J NA+I I V 74 ZAACA REF 2 NA+A V 68 ACeCA 6 8 SPHOA 6~ ZAACA NA+I Vl 70 ACSAA 6 5 ACCeA 63 60 58 ~6 ,ccA, ZKKRA ZKKKA ACCRA 0 2 8 2 8 4 S K2 MN O~ NG3 N 2 , S I 3 N~.8 NITI N NHk N O3t~L~ N 0 3 t K N OAt RAin 0312,TIIN O314 409 6 9 N A 6 ZN 0 4 NA2 O 2 4 1077 ~A2 S I 2 OS A2 9 8 7 NA2 ZNZ S l 2 329 110 NA2 HO O2 07 2 4 1287 N&~ SN2 GE4 0 1 2 19 5 6 1 N A C6 0 7 H7 i~ 115 111 ~ s g ACCRA 1 74 ACRCA 30 78 ACBCA 31 NA*I VII 71 SPHCA IS ;0 NJNlA 113 T ) ACBCA 29 NA*A V I I I 6 8 AGBGA 24 6 8 SPHOA A2 71ANMIA 56 NA+I Xll [ l J$SC8 3 32 ZKKRA 81 Ne.3 vl 7. ACIEA U6 ,8.~ Viii 75 JACSA 9? NR+~ v l 6 8 JCPSA *a 70 JS~C~ l 70 JSSC8 1 70 ~ l A ss $5 PRVAA 98 71J5$CB J 71Z*~c~ 3co 14 J I N C A 36 It JCSI& lVll 1233 6)0 Z4I 811 I0 H)4 NA o I O . I * . Z , 2 0 NA2 AL2 S I S O [ O * 2 H Z 0 NA CL 0 3 INAsAS RAIN 5 2 6 NA U ACETATE 1872 NA2 u O4 8 9 0 NA2 C O 3 . H Z O 9 2 6 NA GO S l 0 4 I NN7 NAA2 I $ O 4 1 3 . 1 5 N 2 0 RqO NA2 OR2 07 ALPHA 1 7 0 3 NA 8 F4 V8? NA~ Z . Z $12 0 7 18 NA3 AL2 L I 3 FAZ 89 NA|3 N833 094 13S NA A~ S I 0 4 RA9 L I NU OZ 2713 NBIOPNI~ 5048 .19 *S~ 90 go3 09 119 1965 AZIO 8 A 2 7 S R 7 . 5 NB2 0 5 . 7 8 ~ - , 8 2 OS NA2 . 8 4 OAA c a NSZ 0 6 C~2 NEZ 07 N ~ l $ NeS~ O94 ~ ~96 0 6 CA2 NB2 U7 8 l ~ NRA7 O * 7 0 756 REVISED EFFECTIVE IONIC RADII IN Table 2 70 ACOC& 2b 7 t ACSAA 25 59 IPHCA 4 73 JSSC8 e 66 ACSA6 20 74 8UFC& 97 N8"5 VII t o JSSC8 1 TL J$$Co 3 ? l ACSCA 27 ; 5 ACBCA 31 N0,2 VIII UNPUI N0+2 i x v~NPUt. ND*3 ?1 INOCA 1o 74 RRSUA 9 ND*3 V I I I b9 JCPSA 50 71 JSSC6 3 lO SPHC& 14 ?u 4C8CA 26 70 ACSAA 24 71 SPHDA 15 71SPHCA 15 74 MR6UA 9 74 Z4AC4 4O3 14 ACOCA 30 ND+J IX TO ACSAA 24 71SPHCA 15 73 6C$AA 27 74 ZAAC& 403 73 ACSA& ZI 73 ~ c s ~ 27 74 AHH|A 5q NO~$ X l l 7Z JSSCO 4 N[*2 Iv bL J A P [ A 32 65 8SCFA 1965 NZ+2 t v SQ b6 [NOCA 5 NI+2 v 67 8APCA 15 NI*2 Vl ?* &HNIA 5e 74 ACBCA 30 68 ZAACA 358 67 8APC& 15 70 ACOCA 28 70 ZAACA 3T8 70 JSSC5 2 7 t PHSSA 438 70 REF I b4 ACCRA t? 13 ACOCA 29 63 Z K K ~ 11o ?4 JCPS& 61 73 JCRL8 3 ?3 &C8C6 29 NI*~ vi LS ?4 ZSAC4 405 71CH0C~ 2tZ NI*3 V] NS 54 JACS& 76 Nle4 Vl L$ &? STGBA ~ 74 J[NCA 3 No+2 V l ?4 [NOCA 73 NP*J v [ 68 J I N C ~ " 3O NP*~ Vi 6? iNUC4 J 14 CJCH4 52 NPt6 Vl 105 354? ?qb 15~ T2 3 045 $14 NSb O26 LI N03 00 I V . YS) NO O~ 8X ~8 O4 N8 P 05 NA3 N8 04 454 89 1610 &?3 N6Z N04 o l t NAI3 N095 09~ I N H 4 ) 3 NO o [ c 2 0 4 1 3 . H 2 NB2 05 ~ o NO [2 NO e L 2 , NO ~R2 922 0A2 NO RO 06 1661 NO AL3 04 012 86 450 518 484 340& b3& ggl 129 I 4&8 N02 HO3 012 NO V 04 K NO U2 O8 NO2 T I 2 o? N04 RE2 Oil NO2 H 0b N04 ~3 015 NO P5 014 ~3 VS V IN0 F31 ND P3 09 2969 g91 2441 I 2813 29?3 12T7 NO2 {C2 0 4 | $ * I 0 . $ H 2 0 N04 M3 015 NO2 IC3 H2 O 4 ) 3 . 6 H 2 o R3 V$ v (NO F31 N02 (C3 H2 0 4 1 3 . 6 H 2 o NO 0~ C O3 N04 HG2 T I 3 $14 022 IL NO A~ o ~ 685 NI CR2 04 1085 SPINEL$ 1200 N] [OPN)2 47 N I 2 P2 07 N i 2 $I 04 NI IPV N 0 J 6 (B F 4 i 2 N[ SE 04 H I 2 P2 Q7 R8 NI F3 $R2 N[ TE 06 RO N[ F3 NI (O H)Z NI2 51 04 1461 N| IC5 H? 0 2 1 2 . 2 H 2 o 2T41Ni $1F6.6H2 0 291NI IH c o O ) 2 * Z H 2 O 852 NI C4 0 4 . Z H 2 0 1 8 1 N I IC5 H7 O 2 ) 2 . ( C 2 N 5 0 2304 H I 3 VZ 08 485 1686 |25 47 1464 12g 416 125 H)2 167 ~2 N* NI F6 2163 H0 N[ O3 14q9 N& NI 02 l R3 VS ~61FLOORIOE$1 L561 K2 N] 2233 EIT[NA?EO 823 NP CL3 32? ESTiNATEO 2175 R~ VS v a3 vs v 186Z s~ NP O6) OH-I II 71 6~X14 OH-I I[[ ~ I 6H~16 oH-I 56 t155 R 0 6 . 6 Feo4 513 012 F 0 H, R[OH-IIIRIF*Z)~.04 56 I I S 5 ~6.6 F E . 4 S13 012 F 0 H. R(OH-I)=8(F-I|+.04 Iv OH-I Vl RIOH-I)IRIF*11*.04 05.4 Vl 6q JC0HA I T 45q 05 02 ?0 ACSAA 24 125 05 02 OS+5 V l 71 ~CSI4 1 9 7 [ 2760 os F5 ?4 SSCOA 14 357 R3 V$ V ICU2 O52 071 56 JINCA 2 79 K 05 F6 0S'6 Vl ~ VS V IPE~OVSKI?~Sl o$+? v l R3 V$ v IPEROV$~iTE$1 05+6 I v 66 ACSA& 20 395 o$ 04 7 ) ACOCA 29 1703 os o4 65 ~ c c ~ 19 157 os o4 7 1 J C S I & 1971 1857 0 5 1 8 . ) - o P*5 Iv t z ACaC& 20 z083 co2 P2 07 60 CJCH6 46 6O5 CU2 PZ o? 65 C~¢H4 43 113~ nGz p z o7 60 IN0C~ 7 1345 C42 P2 o? 71 8SCF~ I v 7 1 426 ZR P2 o? ?o ~C0CA 26 16Z6 H~ p 0 4 . 1 / Z HZ O ?1 ~C0CA 27 2 9 t N4Z H2 PZ 0 7 . 6 H 2 0 ?~ NJNN& [ V ? I 241SR AL3 {P 0412 I0 H ) 5 * H 2 o 69 z x ~ x ~ 130 148 K z ~ z I p O4)3 ?1AC0C6 27 2124 N43 P 0 4 . 1 2 H 2 o 60 ~C$A6 22 18ZZ NA LR2 P~ 012 b8 2KKKA 127 2 1 A L 3 PZ 0 8 . $ H 2 o 68 ClWYA 68 290 Li FE P 04 lO &C6CA 26 1826 H3 p 04 ?2 ANNIA $? 45 NN,65 FE,35 P O~ tZ AG6GA Z§ l g ~ $ | q H ~ | ~ M P U4 73 ACS¢A Z~ 14t LU P O4 I I ACSCA ~ Z~4T CA {H2 p 0 4 ) 2 . H 2 U ?3 AC§¢A ZZgZ A L P 0 4 . 2 H 2 o ?L ACSAA 25 512 K H5 [P 0412 pe$?OvJ$$CB 1 120 ZNZ P2 07 6T JACSA 09 2268 6? Jac$a o~ 227o P*5 Vl 71ZA~C~ 380 5[ ?2 CCJO& l g T 2 676 7J ACAC3 29 266 ~A*~ vl 67 INUCA 3 3Z? 74 CJCH4 52 Z [ 7 5 P~+$ V l z [ ac8c8 27 731 P~*5 I x 67 JC$1A l g 6 T 1429 PBe~ IV PY 63 ZXKK~ 126 98 PI*2 Vl C23 H29 US p CzJ HZ9 05 P p eL5 ET3 N H IC6 H4 0 2 ) 3 P C6LCULAtEO R IP&+41 R3 v$ v ~ P6 O3 K2 PA F7 p$ $1 oJ 1o 4CAC8 PB*2 V I I 9 ZKKK& 4 &CCRA PB*2 v i i i t l SPHCA 64 ACGRA ?3 CJCH4 ?2 HROUA p o * z IX 67 ACCRA 73 GJGHA ?~ ZKKKA ?~ CJGHA P8*Z x 70 ZKKKA P8.2 Xl[ 51 6CCR~ 26 HALIDES 501 p e z 03 09 15 728 P8 w 04 17 1539 PB P2 06 51 ?o P02 V2 O? 7 1025 BI t l T & N A T E S 22 744 PO F2 51 TO P02 V 2 0 t 139 215 P8 c 03 S2 2 7 0 1 P U V2 06 228 P03 P2 08 1o3 p8 IN 0312 R3 VS v IOA $ 041 70 ZKKKA 132 220 P83 P2 00 71 INOC~ 10 1264 K2 P8 CU IN 0 2 1 6 P 6 " 4 IV 72 JCSIA 1972 2448 R3 VS V INA4 P8 041 po** v 7o ZAaC6 375 255 RS2 po 03 PB$4 v I 70 6CAC8 26 501 P02 03 65 JINCA 27 150g PB3 04 74 CJCHA 52 2175 ~3 V5 v po.~ viii 60 N~ou~ 3 153 P8 02 PO*2 I v SQ 67 INOCA 6 730 P0 lob H5 OH3 CHIC 01212 60 J $ [ C A g 166 po I I C 6 H 5 ) 2 CH C2 0212 po*~ vI 68 NRBUA 3 699 R3 V$ V INZ P02 071 73 INOCA 12 1726 XE PO F I [ 6 1 J C $ I A l g 6 1 3?ze K2 po F6 PH*~ vI PH*$ V I I I 74 2AACA 403 I R3 VS v IPX F31 PH*3 I x 74 ZA4C4 403 I 03 VS V IPH F3i PO+4 v l 74 OJCHA 52 2175 R3 v$ v POt4 v i i i R3 VS v ( F L U g R [ T E I PR*J V l t l MRBUA 6 545 R3 V$ v (PR2 N03 0121 P a * 3 VIII 70 SPHCA 1~ 28 PR2 U2 09 74 ZAACA 403 I R3 V$ v (PR F 3 | P 8 . 3 IX 7o SPHCA 15 28 PRZ U2 og 5g ZKKKA 112 362 PR IC2 MS S 0 4 1 3 . g H 2 0 74 ZAAC4 403 I R) v$ v IPR F ) i e~*4 Vl 72 ACBCA 20 956 OA PR 03 ?~ ACBC6 31 971 ~ R t 0Z2 73 JSSC8 U 3 3 1 R IPR941 74 CJCHA 52 2175 R3 VS V PT*2 I V SQ 72 REF 5 PC3 C0 06 Pt*4 vI 89 JINCA 31 3803 PY 02 R3 v$ v 1N2 p l 2 o71 ?4 CJCHA 52 2175 R3 V5 v Pt*5 Vl 67 STBGA 3 I R3 v$ v (FLUORIDES) 67 J C $ I A 1967 478 XE PT F I I pu*~ vt 61 [NUCA 3 327 R I P U * J ) 75 JINCA 37 743 R (PU~31 PU*4 VI b7 INUCA J 32? R IPU*41 73 JS5C6 8 331R (PU*4) t ~ CJCHA 52 2175 R3 VS v PU+6 V l R3 VS v tSA2 SR PU O61 ao+1Vl lO 244c~ 3/5 255 R02 P6 O3 ~ o * z ix 74 ACSCA 30 L640 R02 s 04 RS+I x l 7~ ACSCA 30 1640 R02 s o* RO+I x x i 70 ACSCA 26 1464 R8 N[ F3 ?o J$$C6 2 416 R9 N I F3 70 JS$CB 2 562 86 NI F3 R O - I XXV 65 ACC86 19 2O5 ~8 u 02 IN 0312 aE+4 v i 4 CJCH~ RE+5 v | 70 ACSA~ uNPu2 O8 ACSCA REe6 V l t 5 JS$C6 1o 3 2175 R t vs v 24 3406 N04 RE2 011 co2 aE2 o? 24 6T4 Re CL5 13 77 BA2 HN RE 05 R3 V$ V IPEROVIRITE$1 R V$ VALENCE ~E*? IV b8 ACIEA ? 295 RE2 o? IO H212 7 1 J C $ 1 6 1971 1857 R E I * 7 ) - o 70 CJCH6 40 219 IRE2 I N - C 4 H7 02121 (RE 0 4 | 2 kE÷Z v l 68 ACiEA 7 295 RE2 07 {H2 012 l o 4C8CA RH*~ V l ?3 INOC6 Ru+3 v i CHALCOGENIDES (cont.) 120 213 P8 CAZ $ | 3 17 1539 Pe P2 06 132 AND 26 1876 R,2 o ) 12 2640 ~N F5 R3 vs v I L 6 Ru 03i RU*4 V l ?o ac$64 24 l l 6 RU o z 74 4 c o c , 30 143~ N413-X~ ~U4 0~ 7~ CJCH4 5~ 2175 R3 vs v RU*5 v i ?I J C $ [ A IVTI 2789 RU F$ REF 7 k3 VS V IC02 RU2 o ? ) I ) INOC~ . I Z l / I T X~ RU F I I R U * t IV S4 J6CS~ 76 3317 ~ RU O4 au+u Iv 67 A~$A6 21 T37 RU 04 S+6 Iv GO 6C0CA 24 508 C0 3 04.3 H2 U 7o ZKKK& 132 99 PB2 S 05 ?0 8UFC6 q3 LgO FE $ 04 ALPHA ?o BUFC4 ~3 1e5 FE S 04 0 H 70 6$CFA lg?O 4Z43 n G $ 04 N2 0 71 6C0C6 27 ZTZ N H4 N $ o4 70 NJNIA 113 I NN? NA~2 IS 0 4 ) | 3 . 1 5 H 2 6~ ~CCaA [9 664 NN $ O4 ,i 6c566 ~s 3 2 1 3 N A s H 0 5 4 ° 4 N z ° ?z 6cuc6 28 864 SN 12 N~IU6 Z36 g5 C4 $ 0 4 . 2 H 2 o 72 6C6C4 26 284S x z s O4 T3 JSTCA 14 499 TL2 $ 04 14 ACUC~ 30 g21 C6 $ O4.2N2 o 74 NJHIA 121 208 FE2 IS 0413 S*6 v t 13 ACA¢~ ~9 265 ¢4LCU~6tEO o $0.J Iv ?o A¢$AA 24 320 38 P 04 $0.5 Vl ?o 4 n n t 4 5s 1480 NN? $8 AS 012 71JCSl& I V T l 942 AS $8 f 8 1 1 J G S I A 1911 2318 8R2 $83 F16 74 JC$$8 q 345 Na 58 03 s~*J Vl 68 CJCHA 46 | 4 4 6 S C 2 0 J 60 ARKE4 29 )43 scz oJ U~PU4 5CZ ~ I Z 01 73 5PHCA 17 749 SG2 $12 o? t 3 INOC~ 12 927 SC IC5 H? 0 2 ) 3 73 ACBCA 2V 2615 NA SG 512 06 14 INOCA 13 IS8 SC IC? N5 0 2 ) 3 73 ACSAA 2? 2 8 4 1 S C U H IC3 H2 0 4 1 . 2 H 2 o 69 5PHDA 14 9 NA3 SC 512 O7 sc*J rill 14 INUCA tO 1 3 t SC H ICY H5 0 2 i 4 T2 ACSA4 25 1337 SG2 (G2 0 6 1 3 . b ~ I 0 74 INOCA 13 1a06 H sc I £ 1 N3 0214 74 :NOCA 13 ] e e o . sc I c ? . s o z i 4 $E*O I V be ZAACA 358 125 NN S£ 0 4 , CO $Z 0 4 * N i $ [ 04 b l JGSIA 2]? 968 H2 SE 04 70 ACOCA 26 436 NA2 SE 04 ?o ACeCA 26 1451KZ SE 04 t o ZAACA 37V 20~ N I SE 0 4 . 6 H 2 0 ?2 4C8CA 28 204~ K~ 5E 04 ~9 AC8C4 as [ 9 C U IN . 3 1 4 S~ 04 ?1J$cIA 1971 1857 S e l * 6 1 - o Sl*4 IV 63 NAT~A 50 9 1 F E 2 $1 04 ;~ ZKaK4 137 86 MG2 SI 04 6 I 6CCR4 14 835 NG3 AL2 $13 012 1o ZKKKA 132 I RN5 10 H i 2 S12 00 $8 ACCRA II 437 CA3 AL2 S i 3 012 I G R O S S U L A R I T ( I 71 4 N N I 6 56 I V 3 CUZ C&Z $13 0 1 0 . 2 N 2 o ?1 5PHEA 15 926 ~A Gb $1 13~ 71SPHCA 15 806 V2 5Z OS 71NATWA 58 218 EU2 51 o~ 7o P E P l 6 3 l b l C02 $ I 04 70 ACOCA 25 105 043 S [ 4 Nab 026 71 4 c 8 c 4 27 747 CA2 $ i 0 4 . C A CL2 7| AGBCA 27 848 C42 $I 04 71 &NNIA 56 1222 N A . | 6 K . 8 4 CA4 1518 0 2 0 1 F . 8 H 2 0 71ANNIA 56 1155 HGS*b F E . 4 $13 0 1 2 . ~ F 0 N 69 NS4PA 2 31 L ; N $12 0 6 , H A M S I 2 ~6 CA NG $12 06 69 ~S4PA 2 95 F E 6 * I H N * I NG*8 C A * I $10 022.! IOHII.4 F.5 6g NSAPA 2 101 L 1 2 . 4 N A . I H G I Z . 9 5 1 1 5 . 7 A L * | 0 4 3 . 4 F4o$ I O H I . 3 7o 2KKK4 132 288 C&5 $ I 2 0 t IC 0312 71ACBC& 27 2269 NA2 $ l U J . 6 N 2 0 ?z SPHC4 14 z o z l 8 e z s i o~ 72 4CBC& 28 1899 AL2 BE3 S i 6 018 ; 4 ACOCA 30 2434 112 BE 51 Ok. IX*4 V[ 62 NA[WA 49 34S $1 02 69 CJCH6 47 3859 CU $ l F b * 4 N 2 D ?o ACBCA 26 233 SI P2 o? 71ACOCA 27 2133 SI 02 ? l ACSCA 27 594 CA3 S 1 1 0 H I 6 . | Z H 2 D . $ 0 4 . C 0 3 73 4CBCA 2g 2 7 4 1 N $i F b . b H 2 o 73 ACSCA 29 2748 C0 $ 1 F b * b H 2 0 14 CJCHA 52 2115 63 V5 V SH*2 v l I UNPUl SN 12 SH*2 V i i i UNPUI SN 8R2, SN F2 SH*Z i x vUNPUI. IN CL2, SH 8R2 5M.3 71SPHCA IS 924 NA SN GE 04 $N.3 Vll 70 SPHC& 15 214 SH2 SI2 07 14 SPHCA 1o 575 K2 SN F5 SN*3 V I i i 74 ZAAGA 403 ! R3 V$ V ($N F J I 74 4CaCA 30 Z ? S l SN P5 014 S~*3 ix 69 ACAC8 25 6 2 | SN ISR 0 3 1 3 . e H 2 0 ?o SPHC4 15 214 $M2 $12 o? 14 ZNOC4 13 2eO N H4 SN IS 0 4 1 2 ° 4 H 2 0 7G ZAACA 403 I R3 VS V |SN F 3 | SHe3 X l l 72 JSSC8 4 l [ SN 41 03 SH*~ I V ?~ 6C8C6 31 511 K4 SN 04 72 J C $ I A 1972 2448 R3 V$ V iNA4 SN 041 7J 4C4CB 29 2 b b C4LGUL4TEO SN*~ V 70 6HHI4 ~5 367 SN t 4 Z O? 70 asses 2 410 x2 SN 03 SN*4 v I 69 ZAACA 3be 248 L18 I N 06 70 4C$44 24 128? NA4 $N2 GE4 012 IO N ) 2 74 CJCHA 52 217~ R3 V$ v $N.4 VlII 6 t JC$14 1967 1949 SN IN 0 3 ) 4 5R*Z V l 70 244C4 379 I f 3 ~ c u z 02 72 ZAAC& 393 266 SR 4Gb 04 SR*Z V l l 72 6CBCA 28 3668 SRIO IP 0416 I 0 H ) 2 SR*2 v i i i ~ o, ;: .............. JCPSA 71AKMIA 71ACSCA 74 SPHCA SR*2 IX 69 4C,C4 to ZKKX4 ?2 ACBC4 72 ACSCA 14 SP,C6 s~*~ x ?o AHNIA 74 SPHC4 5~.2 Ill 70 Z&AC4 ? l JS~CO I1NJHHA TA*S vl 71ANN|A 70 JSSC8 71JSSC8 ?o ACOCA b ? ACGR& t**~ vii ?o J$$C8 ? i JSSC~ 14.~ VIII 5 ~ DANKA rs*J~Vl 6U ZAACA t O $ J VIII ?o 5$C06 ~4 266C6 t0*~ Ix ; 4 ZAAGA TO*4 V l 55 1093 SR H 0 4 , SR M o~ $b ?58 $~ c 03 27 2429 SR IN C o 0 1 2 . 2 H 2 0 18 ~75 L42 $R3 04 012 2~ 16~7 s~ 8E~ 04 lJl 455 SR ¢ O3 28 b?9 IR I I 0 3 1 2 . H Z o 28 3668 SR5 I p 0413 0 H 18 675 C6a 5 ~ 64 012 55 1911SR CA 014 020 10 H I b . SH2 o 18 b75 LA2 ~ 3 84 012 378 3 19?1 55 L J 26 23 I 3 90 383 129 SR2 NI IE 06 [ 7 4 SR I~ 03 2 4 1 S R AL3 IP 0 4 ) 2 307 454 145 102 93q SN T62 07 C4 TA4 o11 CA2 o$ 865 t & 4 015 v TA 04 4~4 CA TA4 O i l i~s v4a os T81TA 8 04 14S 182 03 8 1?45 T03 ~E3 o12 403 Z R3 V$ V 178 F31 403 I R3 V5 V I T 8 F3) IO H I S . H 2 0 R. D. S H A N N O N Table 2 72 ACBCA TC*~ VI 67 STBGA I C ÷ 7 IV 6 g MILER 71ZRACA 7E*4 IV b 9 ACBCA 7 l ACBGA 28 9 5 6 B& TO O ) I R3 VS V I F L U O R I O E S ) 3 It JINCA 72 ACBCA 13 ACBCA VII ?2 ACBCA U*6 VIIi 0 9 ACBCA 6 5 ACCRA V*Z Vl UNPU3 V*) VI 70 PRVBA 7J JESTS 6 9 ACECA b 9 ZAACA 74 MRBUA 7 0 JPCSA V*4 V b5 ACGRA b l JCPSA 73 ACBCA 73 ACBCA V*4 Vi 72 JSSC8 T5 JSSC~ 72 PRVBA 74 ACBCA 71ACSAA 7 0 ACSAA 74 PRVBA V*5 IV be RCBCA 6O CHPLB 6 7 ACSAA 70 Z K • K • 71 JESTS 71ACBCA 70 INOCA 1L CJCHA 73 ACBCA 72 JSSCB 13 CJCHA 71CJCHA 73 JSSCB 12 CJCHA 73 CJCHA 73 ACBCA 73 ACBCA 73 CJCHA 757 (cont.) b9 PHSSA 32 73 ACSAA 27 bA INOCA 3 ZN*Z V 70 JSSCB 1 73 CJCHA 51 7 l AMNIA 56 ZN*Z Vl b5 CJEHA 43 6 8 SPNCA 13 70 JSSCB 1 71CJCHA 49 71AHMIA 56 73 ACUCA 29 73 ACSAA 27 ZR*4 IV 75 JSSCB 13 ZR*4 V b 9 CCJOA 1 9 6 9 70 JSSCe 2 ZR*4 vl 6 9 ACBCA Z5 b 9 ZAACA 371 70 JSSC8 L eO A C S • • ~2 ; 3 ACBCA Z9 71ACBCA 2T 14 CJCHA 52 Z R * 4 VII 6 e ACBCA Z5 70 AGBCA 26 70 JACTA 53 73 ACSAA 27 73 ACSAA Z7 11ACBCA 27 ZR*4 viii • b 9 ACBCA E3 b 9 ACBCA 2S b 9 ACBCA ZS 71ACBCA 2T 71AMMIA 56 b 3 INOCA 2 ?L ACBC& 27 b J INOCA 2 33 2 8 6 7 CR2 U 0 6 2 8 3 ~ 8 9 U O2 I 0 H I 2 29 7 U E8 U~6 8 3B0 381 TO2 0 7 146 TCZ 0 7 25 27 I S S L H3 FE2 TE4 0 1 2 CL 6 0 2 T l TE3 0 8 , SN TE3 O8~ TE 02~ HF TE3 0 B , ZR TE$ 0 6 27 60B U 7E~ O9 71ACBCA 7 E ÷ 4 Vl 61ZKKKA ~18 34S 7E 0 2 71ACBCA 27 6 0 2 M TE3 o e 71ACBCA Z? 60B U TE3 0 9 TE,6 IV 11JCSIA Iq71 | 8 S 7 T E ( ÷ 6 1 - O TE~6 V I 6 9 ZENBA 24 6 4 ? L I 6 TE 0 8 7O MRBUA 5 19q RG3 TE O6 b 9 ACSAA 2~ 3082 NA2 K4 TE2 0 8 IO H ) 2 [ H 2 0 ) 1 4 6 4 INOCA b 3 ~ • TE 0 I 0 H I S . H 2 0 6 4 NATMA $l 5SZ • 7E O O H 6 6 ACSAA 2 0 2 1 3 8 K4 TEE O6 10 H ) 4 * H 2 0 I o H•;MA ~7 ~ HG~ TE O6 ?0 ZAACA 3 7 8 129 SR2 NI TE Ob 70 ACSAA 24 3 1 7 8 75 l 0 H I 6 66 ACSAA 2 0 153S TE F6 7L ACBCA Z7 8 1 5 ~G3 TE 0 6 6 5 ZAACA 3 3 4 2 2 3 • TE 0 2 { 0 H I 3 6 8 CHDBA 2 6 7 1433 CUE TE Ob b 9 NOCMB 100 1809 AGE TE 0 2 l 0 H I 4 71 B U F C • 94 172 TE ( 0 H ) 6 73 ACBCA 29 &43 TEE 0 5 13 ACBCA 29 9 5 6 HZ TEZ 0 6 73 ACSAA 27 B§ TE IO N ) 6 7 4 ACdCA 30 1813 HZ TE 0 4 14 ACBCA 3 0 2 0 7 S I N H 4 ) 6 ITE M0b 0 2 4 ) TE {OHI6 7H2 0 THe4 V | 74 CJCHA 5 2 2 1 7 S R3 VS V TH*~ VIii 7 l ACBEA 2? e L ~ K5 TH F 9 1 l ACBGA 2 7 2 2 9 0 • 7 TH6 F31 7~ ICHAA B 2 7 ] K TM P3 0 1 0 ?H*4 IX B8 CCJOA 1 9 6 8 9 9 0 ( N H 4 | 4 TH F8 6 9 ACBCA 2S 1958 I N H 4 ) 4 TH F8 bB CCACA 40 147 • THZ P3 O12 . l O ICHAA 4 STZ N • TN2 { P 0 4 | 3 71ACBCA 2 7 1 8 2 3 R6 TH3 F 1 3 73 ACBCA 2 9 2 9 7 6 NA3 BE 7 H I 0 F4S 70 ACBCA 2 6 1 1 8 5 K NA TH Fb 71ACBCA 27 2 2 T q I N H 4 1 3 TH FT 7H'4 X 7 5 ACBCA 2 g Z 6 8 7 TH I N 0 3 ) 4 ( ( C A H 5 3 3 P 0 ) 2 7H,4 Xl 6 6 ACCRA 20 B42 TH I N O 3 ) 4 . 5 H 2 0 6 6 ACCRA 20 8 3 b TH I N 0 3 ) ~ . B H 2 0 7He4 Xll 6S ACCRA 18 6 9 8 ~G TH I N 0 3 1 b . BH2 O TI*~ Vl 73 JSSC8 6 213 T[4 07 b 3 PHRVA 1 3 0 2 Z 3 0 7 1 2 0 3 74 J $ S C 8 9 2 3 5 712 0 3 74 ACBCA 30 6 6 2 CS T I t S 04)2.12H20 T1÷4 IV 7 3 ACbCA 2 9 2 0 0 9 BA2 T [ 0 4 6L •CCRA 14 8 7 5 8A2 T I 0 4 1 1 J C S I A 1971 1657 T [ I * 4 1 - 0 74 ZAACA 4 0 8 6 0 RB2 T I 0 3 TI*k V 6 8 ACBCA 2 4 132T YZ TI O5 71,4 VI 70 2KKKA 131 2 7 6 Y2 T I 2 0 7 71ACBCA 27 6 ) S NZ H6 T l P6 11JSSCB 3 340 TI~ 07 70 ACACB Z6 ~36 eA TI O)" ~4 •CCRA IT 2 4 0 CO T I 0 3 71 ~cps, B~32~ ,, 72 CSCMC 72 ZKKKA 136 7~ ZKKKA 139 72 INOCA 11 T4 ICHAA 11 74 ACBCA 30 T4 CJCHA 52 TI*4 VIII 66 JC$1A 196B 7L'1Vl TL*t VIII 75 • C B C • 7L÷3 IV 71ZAACA 73 ZAACA 7 4 ZAACA 7L*~ Vl 6 8 ZKKKA 74 ZAACA 75 ZAACA TLeJ Vlll 72 ZAACA TH,Z Vl UNPUl TM*Z V I I UNPUI TM*J V l a 3 PHSSA TM*J r i l l 70 SSGO& Tk Z•ACA TM*3 I X 74 1 A R I A U*~ Vl OB J I N C • U*4 Vl ?3 JSSCB o7 ,NUt, CJCHA u*~ Viii 70 A C B I A T ) ACUCA u,k Ix b ? ACBCA 6q •GBCA TZ A T R I A I $ ACBC& Tk ACBC• u.S vl 6T ACCR~ o2 8A T I b O13 T[ 02 K TIP 05 ITi O(CB H7 0 2 1 2 1 2 (NHA)2 TI O(C20~elE.HZ 8A T I Z O5 R3 VS V 273 103 2989 243 2894 21TS 1496 T[ O {N 0314 R3 VS V I N F ) 3 6 5 TL N 03 31 LI5 TL 0 4 IT3 SR4 TL2 O7 19T BA2 7 L 2 0 S 381 396 403 IZ9 12& 409 AIZ 143 TL2 0 3 l g 7 BA2 T L 2 0 S S7 R8 71 F4 393 2 2 3 TL F ) TH IZ TM C L Z , T M BR2 3 K4Ab TM2 0 3 8 174S TN3 FES O12 4O) I k ~ v S v ITM F ~ ) 403 I K) 3O vS V ITM F31 B 331 R3 VS V , 3. R ,u.4, SZ 2 1 / S R3 V$ V 23 | 9 1 9 2S 2 1 6 3 Z7 245 29 4&O )u le66 U FB K U2 F 9 K2 u P6 C~ U6 EZ~ CS U2 F 9 B - NH4 u FB Z~ B65 t S A~ BUFC~ OT B U F C • U*3 VII T$ SPNCA U,6 vl oE &CBCA =e ACBC~ 6B vO 21k U CR 2BT U FE U4 1| ~23 U2 RO 0 8 2" ZS q 6 7 CU u 0 4 /OT SR u o * , 8~ u O4, CA2 U O~, $~Z u U S , CA3 U OB,SR~ U O6 J0~0A 23 4 7 7 CO u ; I .INU~A ..... U F8 I . .4SB . . . . u. . .0.3. . 4 NJMMA V SO ACSAA 71RVCMA 7 4 ACBCA 74 ACBCA 7 3 ACECA TO CMOCA V*5 Vi 73 JSSCB 11ACSAA ZZ CJCHA 73 CJCHA T~ CJCMA 73 ACBCA M*3 Vl bT STBGA M+6 IV b 9 ACBCA ~1SPHOA T I SPHCA 72 ACBCA 71JCPSA 25 19 7 8 7 CA U 0 4 2 0 5 RB U 0 2 IN 03)3 V F2 2 3771 6 419 2 5 1334 369 306 9 1091 31Z~69 V2 0 3 V4 O7 V I C 3 H7 0 2 ) J N VZ 0 4 IV0.99 CRO.01IZ V2 O3 19 4 3 2 SS 53 29 269 2 g 1335 L I V2 0 5 V O I t S H7 0 2 1 2 CA V3 0 T CA V4 0 9 03 5 4 4 6 CU V 0 3 A 419 vk at 5 2361V OZ CR S0 2 6 ~ 4 V3 0 7 2 5 2 6 7 5 Vb 0 1 3 Z4 4 ~ 0 V02 I0 4 9 o VO2 24 292 2 47 2L 590 13l 161 3 4~a 2~ 2 1 2 4 2259 4V 1 6 2 9 29 2304 4 29 51 1 0 0 ¢ A9 3 0 S 6 6 $38 50 3 9 6 4 $1 70 29 14! 29 133B $1 265 Y V 04 ER V 0 4 MN2 VZ 0 7 5&3 I V O412 NO V 0 4 NA3 V 0 4 . 1 2 H 2 0 CA2 V O4 CL MG3 V2 0 8 C03 VZ 0 e , N i 3 FE v 0 4 ZN2 VZ 07 ZN3 V 2 0 B L 1 3 v O4 CU3 v z 0 8 PB2 VZ O7 Y V 04 CUB VZ O10 Li V 03 vz 08 ZI0 CAS I V 0 4 1 3 0 H 3 0 25 |704 13 b 5 6 13 92B 28 3 1 7 4 5 5 IO93 ACBCA 30 T~ ACBCA ~O V T4 ACBCA 3O M.6 Vl 6 9 SPHCA 13 b 9 SSCOA 7 70 SPHCA 14 10 SPHCA 14 7 0 SPHCA 15 T0 ACBCA 26 7 0 JSSCB 2 66 ACSAA Z0 72 ZENSA 27 T I SPHCA 13 74 JSSC8 10 74 •CBCA 30 XE,~ IV 71JCPSA $2 71JCSIA lg71 xE*e Vl 6~ INOC, 3 6 h INOCA 3 K2 H 0 4 N02 M 0 6 PB M Ok SN w O4 SR M O 4 , B A M Ok 1872 N • Z "M 0 4 l e t 8 • L Z IM O~33 W*6 V,3 Z3e7 CA3 M O~ CLZ 933 1797 B18 $15 28 1020 Z/8 269B ZO3 991 3 2069 HG H 04 6 1 2 M O& K NO (M 0 4 ) 2 L i 2 FE MZ OB PRZ MZ 0 9 CU M O4 LIFE (H O4)2 H Fb IGAS) SN M 0 4 N~4 M3 013 FEE N 0 b 6A M 0 4 8 | 2 XE 0~ 1837 XE{+8)-O 1~12 NA4 XE 0 6 . B . 2 0 1417 N • 4 XE 0 6 . B H Z 0 K4 XE 0 6 . 0 H Z 0 Vl 6T ACCR~ ZZ 67 SPHCA 6 9 ACBCA 11 ~83 A Y 2S 2 1 4 0 Y2 0 3 ............. 3Sk YZ BE O4 ~R TZs~% 71sp.c• 1~ Bo6Yz Sl OB ~k J C S l A 1 9 7 k 2 2 9 C6& H I 2 [ 3 N12 0 6 Y Y*3 V l i 6B INOCA T 17TT YIC6HSCOCHCOCH3J~.H20 Y*3 V l l i 6~ AC~CA 24 Z92 ~ V O~ 57 AECRA 10 Z39 Y3 FE5 0 1 2 o 8 EPHOR 12 1095 • Y NOZ 0E 6 9 SPHCA 13 4 2 0 • Y ~2 U8 ,O~R~,, l,l ~T MICRA 14 ZAACA IX S9 Z • K K A 1 , ZAACA YB*Z V l 11Z•ACA YB*Z V I I 74 ZAACA 71ZAAC• Y6e¢ v i i i T l ZAACA YB,J vl 7u SPHCA 10 •CBCA 70 ZAACA 74 ACBCA YB'~ Vll 70 SPHCA ~ INOCA O9 INUCA YBe3 V I I I T0 INOCA ~o $SCOA Z3 ~03 ZAACA YB*~ IX I k ZA~CA ZN,Z i v ~a S P . 0 A 6V ACBCA ko3 .SYZ.20T 9 3 9 Y 7A 0~ I R ) VS v Iv F~) ||Z 40~ 3bZ Y I C 2 HS S 0 k l 3 . 9 H Z I R3 VS V I Y P ~ | 3B6 22| 4O3 JSb 4~ Y8 e L 2 2 2 1 Y B 8R2 JB6 ZZl YB BR2, YB FZ 14 85A 26 4B~ J77 T0 3 0 18S7 I~ B 8 YBZ SI O5 YBZ S12 O7 C • v~Z 0 ~ , SR YBZ O4 Y6 P3 0 9 B3~ YB2 S l 0 5 ZZ VB I t 5 MT O I l 3 2 9 VB ICE HT O Z l J 9 109b YU L I F k 8 174~ YBJ FE3 01Z ~OS IZ 23 O Y8 12 v. V lYE FS! I M3 vS v lYE FSI eeT N • Z ZNZ S l Z O7 I Z 3 ) ZN 0 I ~ Z OI IHZ 03 1 / Z C6 0 0 ZTB R3 VS V IM~ ZR OAI 7 2 7 K2 ZR 0 3 4 1 0 KZ ZR 0 3 2658 306 478 Ia2Z 2294 ZR (M AS 0 4 I Z . M Z L 1 2 ZR 0 3 • 2 ZRZ OS ~ • ZR2 P 3 0 l Z L I Z ZR F6 1944 RBS ZRA F Z I 2 1 7 5 R3 V S V 0 21e4 417 12b 177 Z614 1944 NAZ ZR F6 I N H 4 1 3 ZR F t ZR OZ ZR4 I 0 N l 6 (CR 0 4 I S . H E ZR ( 0 H I Z S O4,.MZ 0 Re5 ZR4 F21 1558 IB66 IStZ 63B Tee 243 1944 250 ZRZ (S 0 4 1 4 I H 2 O I B . 6 H 2 ZR2 i S 0 4 1 4 (HE O I B . E H Z ERE I S 0 4 1 4 . § H E 0 NZ H6 ZR F6 ZR S I Ok ZR ( A C A ¢ I 4 RE5 ZR4 F 2 1 NA4 ZR ICE 0 4 ) 6 * 3 H 2 0 0 0 O R.M.G.MVC•0FF,CRYSTAL STRUCTURES,WILEY, N.Y.eI96B H.BARNIGHAUSEN ET A L . , P R O C . 1 0 7 H R . E . RES.CONF.CAREEREE,AR|ZII973)P.490 C.BRANOLEeH.STEiNFIN•.PROC.7TH R.E. RES.CONF.eCORONAOO,CAL.OCT 2 8 , 1 9 6 § R.D.SHANNON,U.S.PAT.3&bSIBLtNAYIb.1972 W.H.BAUR,NITROGEN,HANOBOOK OF GEUCHEM. SPRINGER-VERLAG,N.Y.1974 A.M.SLEIGHTtU.S.PAT.38&9544,NOV 19,1974 H.BARNIGHAUSEN,PERSONAL COMMUNICATION A.M.SLEIGMTePERSONAL COMMUNICATION C.C•LVOePERSONAL COMMUNICATION C . T . P R E M I T T , P E R S O N A L COMMUNICATION M . H . B A U R , P E R S O N A L COMMUNICATION REF 7 UNPUI UNPU2 UNPU3 UNPU4 UNPUS I R3 VS V { F L U O R I O E S I IO H ) 2 . 2 H 2 1147 ZN2 PZ 0 7 127 ZN M 0 4 1 2 0 ZNZ P2 0 7 3 0 S b Z N ) V2 OB 1 1 k 7 ZN4 AS2 0 8 IO H I 2 . 2 H Z 2741Zfl S| Fb.6H2 O 1 5 4 l ZN S 0 3 . 2 I / Z M Z 0 G. REF S REF b 432 V P 05 2 6 7 5 V6 0 1 3 3619 NG V2 06 2621V P O3 ALPHA 2 1 8 4 K3 V OZ C2 O 4 . 3 H Z 1743 GU VZ 0 6 3 25 50 $1 52 29 0 KEF | REF 4 4 1119 vz 05 8 ~O9 Li V2 0 5 30 2 6 4 4 V3 0 7 30 2 4 9 1 H G Z V2 0 T 29 S&7 HG2 V2 0 7 270 9SZ CA VZ 0 6 1 2 0 ZN2 P2 0 7 I 0 0 4 ZNZ V2 0 7 1 1 4 7 ZN~ AS2 0 8 REF 2 REF 3 3~ 16~BN, v 0 3 V*5 Y*~ B23 R l U * 3 ! 26 3B I N H k ) 4 Z9 IV 4Z U e L 4 ~,,CRCA 28 3609 U 03 KQ| ZN FEZ 0 4 1541ZN $ 03.2 1/2H2 2 6 5 . ZN 10PMI2 ACACB ACOCA • CCRA ACIEA ACSAA ADCSA • MMIA ANCPA AR•EA BAPCA BCSJA 8SCFA OUFCA CANIA CCACA CCJDA CHOBA CHOIR CHPLB CIMYA CJCHA CSCMC CZYPA DANK• HCACA ICHAA INOC• |NOMA INUC• iVNMA J•CSA JACG• JACTA JAPIA JCNLB JCOMA JCPSA JCSIA JCSPA JESUA JIHCA JMOSA JNBAA J0P~A JPCHA JPCS• JSbCS JSTCA JUPSA HNLHB H0CMB HRBUA MSAPA NATUA NATMA NJMIA NJMMA PEPIA PHSSA PlS•A PISUA PRLAA PRVAA PRVBA p~r~VA RICPB RVCMA SCIEA 5PHCA SPHOA SSCO• STBGA TPSU• MP~[& UNPUI ZAAL& E. BR0~N, PH.0. THESIS, VIRGINIA POLYTECH.INST.,UNIV.MICROFILNS,TE-49B ACTA t R Y S T . SECT. A ACTA CRYST. SECT. B A C I A CRYST. ANGEM. CHEH. I N T . EO. ACTA CHEM. SCAND. AOV. CHEM. SER. AM. M I N E R . ANNLS C N I H . ARK. KEM] B U L L . ACAO. POL. S C I . SER. S C I . C H I H . B U L L . CHEN. SOC. JAPAN B U L L . SOC. C . I M . F R . B U L L . BOG. F R . H I N E R . CMISTALLOGR. CAN. MINERALOGIST CROAT. CHEM. ACTA CHEM. COMMUN. C . R . HEBD. SEAN. ACAO. S C I . SEA. B C . R . HEBO. BEAN. ACAO. S C I . SERe C CHEM. PHYS. L E T T . C•RNEGIE iNST. MASH. YEARBOOK CAN. J . CHEN. CRYST. STRUCT. COMM. CZECH. J . PHYS. 0 0 R L . AKAD. N A U • , SSSR H E L V . CMIM. ACTA INORG. C H I N . AGTA INORG. CHEM. RUSS. J . INORG. CHEM. INORG. N U C L . CHEM. L E T T * I Z V . A • A D . NAUK SSSR, NEORD. CHEH. J . AH. CHEM. SOC. J . A P P L . CRYSIALLOGR. J . AM. CERAN. SOC. J . A P P L . PHYS. J* CRYST. MOLEC. STRUCT. J . L,'SS-¢OHMON METALS J . CHEM. PHYS. J . CMEM S a c . LON0. 10ALTOM) J * CHEM. SOC. LONO* ( P C • K I N I | ! J . ELECTROCHEN. SOC. J . INORG. N U C L . CHEM. J . MOLEC. SPECTROSC, J . RES. N A T . SUB. STAND. SECT. A J . P~YS. I F R . | J . PHYS. CHEM. J . PHYS CHEM. SOLIOS J . SOLID STATE CHEM. J . STRUCT. CHEM. J . PHI'Be SOC* JAPAN MINERALOG. M•G. MH* CHEM. MATER. RES. B U L L . H I M . $ 0 C . AMER. SPEC. PAPER NATUREILONO. NATURMISSENSCHAFTEN NEUES J S . H I N E R . ASH. NEUES J B . M I N E R . N H . PHYS. E•RTH P L A N E T . INTERIORS PHYS. STATUS S O L I D I PRUC. I N 0 1 • N ACAD. $ C I . A PROC. I N D I A N ACA0. S ¢ I . 8 PROC. R . SOC. SERIES A PHYS. REV, SECT. • PHTS. REV. SECT. 8 PNTS. R e v . RECL TRAV. C H I N * PAVS-BAS REVUE C H I N . MINER* CPR.) SCIENCE SOVIET PHYS. CRYSTALLOGR. SOVIET PHYS. OOKL. SOLID ST•TE CO"MUM. STRUCT. AMO BOND. ;RAMS. F A • • O A Y s a c . . TSCHERMAKS M I N E R . PETROGR. M I T T . I U , P U B L I S H E 0 REFEREMGE) Z . •NORG. • L L G . CHEM. Z•~R• Z. KRISTALLOGR. MINER. ZEPY• ~ . P . v S . ZE~BA . NArURF. Z S T • I ZM. STRUKT. • H I M , 758 REVISED EFFECTIVE I O N I C R A D I I IN H A L I D E S compounds to be slightly larger than those of the E u 2 + compounds. This difference was assumed to exist for all Sr z+ and Eu 2+ coordinations. Because compounds of Am 2+ and Sr 2+ have similar cell volumes, the radius of Am 2+ was made equal to that of Sr 2+ Wolfe & Newnham (1969) studied Bi4_xRExTi3012 and concluded that Bi3÷ and La 3+ have nearly equal radii. From a study of BiTaO4 Sleight & Jones (1975) have concluded that although Bia + and La 3÷ have essentially equal radii, the size of Bi3÷ depends on the degree of the 6s 2 lone-pair character. When BiTaO4 transforms from a structure where the lone-pair character is dominant to the LaTaO4 structure, it undergoes a volume reduction. Table 3 shows a comparison of isotypic Bia+ and La a+ compounds where the lone-pair character of Bi3+ is (1) constrained and (2) dominant. Bi pyrochlores such as Bi2Ru207, Bi2Ir207 and Bi2Pt207 were omitted from the table because no corresponding La pyrochlore exists, but they have unit-cell volumes close to those of the Sm or Nd pyrochlores and thus have smaller volumes than those of La. When Bi3÷ is forced into high symmetry, a Bi 3+ compound has a smaller volume than that of La 3+, but when the lonepair character is dominant, the Bi a+ compound is distorted and Bi 3÷ and La a+ compounds have approximately equal volumes. This behavior was also noted in the highly symmetric garnet structure where the hypothetical BiaFesOlz was estimated to have cell dimensions between those of the hypothetical NdaFesO12 and Pr3FesO12 (Geller, Williams, Espinosa, Sherwood & Gilleo, 1963). For practical purposes, Bi a+ is listed as slightly smaller than La 3+ but this dependence on lone-pair character must be kept in mind when comparing the volumes of Bi a + and La a+ compounds. Similar behavior may also exist for Pb 2+ and Sr 2+, but this relationship was not investigated. Table 3. Cell volumes of isotypic Bi 3+ and La 3+ compounds (a) Lone pair character of Bi a+ constrained Compound BiLi(MoO4)2 LaLi(MoOa)z BiNa(MoO4)z LaNa(MoO4)2 BiOF LaOF Cell volume 314.7 328.7 320-5 332.1 87.6 97.7 Ratio 0.96 110.7 116.8 123.8 126.4 293-0 304.7 0.95 BiOCI LaOC1 BiOBr LaOBr BiPO4 LaPO4 (b) Lone pair character of Bi a + BizMoO6 LazMoO6 BiFeO3 LaFeO3 Bi2Sn207 La2SnzO7 dominant 268.5 ( × 8) 267.3 62.49 ( x 6) 60.77 ( x 4) 1219.9 ( x 8) 1225.3 AND CHALCOGENIDES A similar study of relative cell volumes of isotypic compounds involving the pairs Cu÷-Li +, Ag+-Na +, TI+-Rb ÷, and pb2+-Sr 2÷ was used to obtain more reliable estimates of the radii of Cu +, Ag +, TI ÷, and Pb 2÷ (Shannon & Gumerman, 1975). The nature of Sn 2÷, NH~-, and H - made it impossible to define their ionic radii. The coordination of Sn 2÷ by oxygen or fluorine is always extremely irregular,* leading to average distances which depend on the degree of distortion. Since this distortion varies widely from one compound to another, it is not meaningful to define an ionic radius. Khan & Baur (1972) derived an apparent radius of the NH4+ ion by analyzing the N - O distances in a large number of ammonium salts. They concluded that NH + has an octahedral radius of 1.61 A, between that of Rb ÷ (1.52 A) and Cs ÷ (1.67 A). Alternatively, cell volumes of NH~ and Rb ÷ fluorides, chlorides, bromides, iodides and oxides may be compared. This leads to the conclusion that N H ~ is not significantly different in size from Rb ÷. No explanation is offered for this inconsistency and therefore the radius of NH~ is not included. The radius of the hydride ion, H - , has been the subject of some controversy. A number of different radii have been proposed: 2.08 (Pauling, 1960); 1.40 (Gibb, 1962); and 1.53 A (Morris & Reed, 1965). Gibb studied interatomic distances in many hydrides and concluded that good agreement between observed and calculated distances could be obtained using r(V~H -) = 1.40 A if corrected for cation and anion coordination. The value of r(IVH -) was taken to be 1.22 A. Morris & Reed (1965) concluded that differences in observed distances in hydrides were caused by the large H - polarizability. Because of such wide variations in the apparent H - radius, it was omitted. However, an explanation for the variations based on covalence differences will be discussed later. * Although cell dimensions of Sn2M207 pyrochlores were used in SP 69 to derive r(VmSn2+), Stewart, Knop, Meads & Parker (1973) and Birchall & Sleight (1975) recently found that the pyrochlore A site in Sn2Ta207 is not fully occupied. Thus, even this example of apparently regular Sn 2÷ polyhedra is not valid. 0"97 I .90 0.90 .80 I I I I V 0.98 0.96 .70 1-00 .50 1"03 ,40 1"00 ~---------"~ To "91' - I +2 r I I 4"5 +4 +5 OXIDATION STATE Fig. 1. Effective ionic radius (,~) vs I .+6 +7 oxidation state. • R. D. SHANNON Results and discussion In Table 1 two sets of radii are included. The first is a set of traditional radii based on r(V'Oz-) = 1.40 A. The 2.oo1---~--~ . . . . I r - I -- I I 1 I 1.901 759 other set is based on r(WO z-) = 1.26 and r(V~F-)= 1.19 A,, and corresponds to crystal radii as defined by Fumi & Tosi (1964). As pointed out in SP 69, crystal radii differ from traditional radii only by a constant factor 1.70 I J . 1.60 1.50 1.40 1.30 , . . . . . 1.50 Rbd 1.70 , 1.60 Cs - ~iaoi , 1.40 1.30 1.20 1.10 r 1.00 .90 1.20 .80 ~ 1.10 Y0 1.00 .60 • .90 Li + Ni2-~ .50 80 Be + .4O .70 .30 .60 .20 .50~ I 4 I I I I 5 6 7 8 CN I I 9 10 ill 12 I .10 13 2 CN (a) I I 1 • 1.20 (b) I . I I . - ~Bi3+ . . . . , 1.10 J 1.00 • j . I i I I la3F+~] ~.~TL3÷ 1.30 .90 .80 p 3+ .70 .60 .50 A0 .30 _ B °/ ~ ~ 3 Go3+ 1.10 ~_---~-Tb 3+ AI 3+ ~Tm 1.00 - Er .. ~""~'~"Lu-'yb3÷ -. .90 + .20 Zi .10 = .7 0 CN I 7 I 8 9 CN (c) F i g . 2. I 6 . (d) (a)-(e) Effective ionic radius ( • ) vs C N for some common cations. 1 10 !i ] 12 760 REVISED EFFECTIVE I I t I I I O N I C R A D I I IN H A L I D E S p.4+ VXOs6+, VlRe6+, and V1Os7+. The symbol A means that Ahrens (1952) ionic radius was used whereas P means Pauling's (1960) crystal radius was used. The symbol M means that the radius was derived from a comp o u n d having metallic conductivity. Distances calculated from these radii may be too small for use in compounds having localized electrons. (See discussion Bk 4+ Effects of electron delocalization.) I I I '1 Th 4÷ 1.20 i.I0 !.00 ~ .90 :Hf4 + .80 Ti 4+ ~/4+ .70 .60 / .50 .40 .30 y AND CHALCOGENIDES Ge4+ Si + .20 In addition, the sources of the radii are indicated in Table 2. Fig. 2(a)-(e) shows that r - C N plots are reasonably regular. Notable exceptions are IVNa+, VNa+, and ~VK+. It is apparent that N a - O and K - O distances do not decrease as much as anticipated from the r - C N curve* when the CN falls below six. Typical distances and corresponding radii in Table 4 show that N a - O distances in four-coordination are only slightly less than in six-coordination. The reduction in interatomic distances is caused primarily by the decreased repulsive forces due to fewer ligands according to the expression of Pauling (1960): Rc.<c~_[ANacl Bc,c~_]~I('-~) .10 RNaCl CN (e) Fig. 2. (cont.) of 0.14 ~ . Although their inclusion in Table 1 may seem superfluous, it is felt that crystal radii correspond more closely to the physical size of ions in a solid. They should be used, for example, in discussions of closest packing of spheres, structure field maps (Muller & Roy, 1974), and diffusion in solids (Flygare & Huggins, 1973). Traditional radii have been retained because of their familiarity to crystal chemists and physicists. They will probably continue to be used for comparison of unit-cell volumes and interatomic distances. In the table, the ion is followed by electron configuration (EC), coordination number (CN), spin state (SP), crystal radius (CR), and effective ionic radius (IR), and in the last column, a symbol indicating the derivation of the radii and their reliability. Those with a question mark are doubtful because of: uncertainty in CN, or deviation from radii vs CN, or radii v s valence plots. Where at least five structural determinations resulted in radii differing by no more than + 0.01 A, the values are marked with an asterisk. When the choice of a radius was influenced by any of the various correlations described earlier, it is indicated by the following: R - from r 3 vs unit cell volume plots; C - calculated from bond length-bond strength equations; E - estimated from one or more plots of r v s valence, r v s CN, and r vs cell volume. E implies poor or nonexistent structural data. Radii in this category include VIFeZ+LS, WMn2+LS, vlcIa+LS, vIV2+, VINo2+ ' VINia+HS, wit3+, WMo 3+, VITa3+, Wpaa+, VlTa4+ ' IVpb4+ ' V~IrS+' WOsS+ ' WReS+, WpuS+, WBiS+, L Acscl BNaCl where R = i n t e r a t o m i c distance, A = M a d e l u n g constant, B = t h e cation CN and n = Born repulsion coefficient. It appears that this equation is not valid for four-coordinated Na ÷ or K +. There are a few small irregularities in r - C N plots probably caused by poor or insufficient data, e.g. curves for TI 3+ vs y3+. The differences in slopes of Ti 4+ VS C r 4+ and V s + vs As 5÷ are probably caused by Ti4+-O and V5+-O octahedra being generally more distorted, which leads to greater average interatomic distances. It is also interesting to compare distances in square planar coordination v e r s u s tetrahedral coordination. Radii of square planar Cu 2÷ and Ag ÷ are equal to or slightly greater than corresponding tetrahedral radii, consistent with the trend anticipated from anion * Extrapolation of the Na curve gives r(~VNa÷)=0-90 A. \ Ul S b . . . . . . " -' .'!ll, [ \ , %. i\", (.9 Z "' n,, .~% ~ ........ I- - -t~ --~,, ', ci I I ! i 7 !I ii I",,:, I I I i I _1 I ° "' s, ....... ~ ~ "__'__i Ti- - Ti ~ I i ', - ]l , ~ I Rb R! R2 R, AVERAGE INTERATOMIC DISTANCE , R Fig. 3. Typical bond length vs bond strength plot. R. D. S H A N N O N repulsion effects. A similar comparison with Fe 2+ and Ni 2+ cannot be made because of electron distribution changes from tetrahedral to square planar coordination. I i 2.05 , -v'r NbS+ 2.03 2.02 2.01 ~¢~) 2.00 1.99 1.97 1.96 1.95 ii 1.94 i •002 [ i .004 .006 .008 i i I .010 .012 .014 .016 Fig. 4. Mean NbS+-O b o n d length v s distortion. Vertical bars represent average e.s.d.'s quoted by the authors. Solid circles represent m o r e accurate data. r 2.o0 i i "v'r M06 + 1:98 1.97 1.95 1.94 J 1.911 1.90 R (/~,) 2.40 2.37 2.36 2.39 Mean 2-38 2.38 2-37 2"39 2.48 2.44 2.41 2-415 2.45 2-460 2.375 2-406 2.42 r (/~) Reference 1-02 0.99 1.00 0.99 1.00 60 A C C R A 13 57 A C C R A 10 69 Z A A C A 4 0 9 1.00 1.01 1-02 1.10 1.06 1.04 1.05 1.10 1-09 1.025 1.046 1.05 74 65 70 64 65 67 61 67 63 59 75 A C B C A 30 A C C R A 19 A C S A A 24 A C C R A 17 A C C R A 18 S C I E A 154 A C C R A 14 A C C R A 22 A C C R A 16 A C C R A 12 A C B C A 31 263 462 69 1872 561 1287 672 818 1453 555 182 1233 526 19 Additivity of radii to give mean interatomic distances is not so important to the synthetic chemist who is primarily interested in ionic radii for predicting substitution in crystal structures. Crystallographers and physicists, however, are concerned with comparing calculated and experimental interatomic distances and predicting distances, e.g. for distance least-squares (DLS) structure refinements (Baur, 1972; Tillmanns, Gebert & Baur, 1973; Dempsey & Strens, 1975). The effective ionic radii in Table 1 can be used to reproduce moderately well most average interatomic distances in oxides and fluorides. However, certain deviations do occur. Some of these are unexplained but others can be attributed to (1) polyhedral distortion, (2) covalence, (3) partial occupancy of cation sites, or (4) electron delocalization. R=1.920 + 3 . 7 3 A 1.99 1.93 Compound (a) lVNa+ Na20 NasP3010 NaOH.H20 Na6ZnO4 Factors affecting mean interatomic distances 1.9e 2.01 Table 4. lnteratomic distances in some compounds containing tetrahedral and octahedral Na + (b) VlNa+ Na2WO4 NaC6OTH7 Na4Sn2GeaO12(OH)a Na2P2OT. 10H20 NaHCO3 Na2B406(OH)2.3H20 Na4P4OI2.4H20 NaAI(SO4)2.12H20 NaB(OH)4.2H20 N a U acetate CloHI3NsNaO6P.6H20 Mean R= 1.976 + 6.45 A 2.04 761 ~ .002 , .004 F i g . 5. M e a n ~ , .006 .O08 M06+-O v .010 Z~ bond , .012 ~ .014 , .016 .018 l e n g t h vs d i s t o r t i o n . 1. Polyhedral distortion To see the effects of polyhedral distortion consider the relationship between bond length (R) and Pauling bond strength (s) (Brown & Shannon, 1973). The analytical expression S=So(R/Ro) -N, where So is an ideal bond strength associated with R0, and R0 and N are fitted parameters, was evaluated for cation-oxygen pairs for the first three rows of the periodic table. Using these relationships, the sums of bond strengths about cations and anions were found to equal the valences with a mean deviation of about 5 %. Accepting the approximate validity of Pauling's second rule, p = ~s where p = valence, it is possible to derive the effects of distortion of various polyhedra on their mean bond distances. Fig. 3 shows a typical R-s curve. An undistorted octahedron results in an average bond strength g and a mean distance/~a. A distorted octahedron with three bonds of length R= and three of length Rb results in the same average bond strength, g, but a mean distance Rz >/~1. 762 REVISED EFFECTIVE IONIC RADII The effects of distortion on m e a n bond lengths in numerous polyhedra have been determined. Although distortions in tetrahedra are not as important as in octahedra, they can contribute to variations in m e a n tetrahedral distances (Baur, 1974; Hawthorne, 1973). Strongly distorted octahedra like those containing V 5+, Cu 2+, and M n 3+ show a significant variation in m e a n distance with distortion, A* (Brown & Shannon, 1973; S h a n n o n & Calvo, 1973a; Shannon, G u m e r m a n & Chenavas, 1975). Octahedra containing Mg 2+, Zn z+, Co 2+, and Li + are generally less distorted than those of V 5+, Cu 2+, and M n 3+ and show a less pronounced dependence on m e a n bond length (Brown & Shannon, 1973). The effects of distortion on m e a n bond lengths in N b S + , O and M o 6 + - O octahedra are illustrated in Figs. 4 and 5. Tables 5 and 6 list the data used to derive the figures. Table 7 lists the results of linear regression analyses of m e a n bond length on distortion for all octahedra studied. It is clear from Fig. 4 that undistorted N b 5+ octahedra in pyrochlores have a distinctly smaller mean value than in compounds like NbOPO4, CaNb206, and NaaNbO4. Most of the accurately refined molybdates have relatively distorted octahedra. However, certain ordered perovskites with no octahedral distortion such as BazCaMoO6 would be expected to have much smaller m e a n Mo6+-O distances than a typical molyb* Octahedral distortion is defined by A=~Y(R~-R/R) z where R=average bond length and Rl=an individual bond length. IN HALIDES AND CHALCOGENIDES date. In fact, the M o 6 + - O octahedra in Mo2(O2C6C14)6 with a very small distortion have the short mean distance of 1.919 A. Table 7 also lists the results of regression analyses for TaS+-O and W 6 + - O octahedra but they are only approximate because of the scarcity of accurate structural data. Analysis of Ti4+-O octahedra was unsuccessful because of scatter in the data. Distances in Ba6Ti17040 (Tillmanns & Baur, 1970) and BaTiO3 (Evans, 1951) deviated significantly from a linear relation. Relations between m e a n distance and distortion should be particularly useful to help determine oxidation states in mixed valence compounds with such combinations as MoS+-Mo 6+, W s + - W 6+, v a + - v 5+, Nb4+-Nb 5+ and Mn3+-Mn 4+. Such considerations helped rationalize M n - O distances in NaMnvO12 and the mineral pinakiolite (Shannon, G u m e r m a n & Chenavas, 1975). The radii in Table 1 are generally derived for an average degree of distortion. Thus, interatomic distances calculated from these radii m a y be inaccurate if the distortion in a particular c o m p o u n d is much less or greater than usual. This applies particularly to cations whose polyhedra frequently show a large distortion, e.g. MO 6+, N b s+, V 5+, Ba 2+, and the alkali ions. 2. Effects of partial occupancy of cation sites on mean cation-anion distances In compounds with partially occupied sites, abnormally large c a t i o n - a n i o n distances are usually found, as expected if the anions surrounding unoc- Table 5. Compar&on of mean octahedral N b s + - O distances with distortion Only structures with e.s.d.'s for Nb-O distances of < 0.025 ~ were used. Compound HgzNb207 Cd2Nb207 NazNb4Ol i Ba0.27Sr0.75NbzOs.Ts NalaNbasO94 Ba3Si4Nb6026 Na13Nb3sO94 Nax3Nb35094 Na13NbasO94 NaNbO3 NalaNb35094 Na13Nb35094 Na13Nb35Og4 Na13Nb35094 LiNb308 LiNbO3 Ca2Nb207 Ca2Nb207 SbNbO4 KNbO3 NaaNbO4 CazNb207 Ca2Nb207 Na3NbOa CaNb206 GaNbOa /~ (/~) 1.999 1.957 1.977 1.967 1"965 1"989 1"967 1.959 1"964 1.985 1"947 1"991 1"987 1"978 1-993 2"000 1.997 2.005 2.003 2.011 2.013 2.010 .2.015 2.021 2.021 2.031 Distortion /t = ((AR/R) 2) × 104 0 0 1 6 7 9 11 12 12 16 18 22 22 24 28 31 31 34 37 42 52 53 58 60 76 83 Reference 68 INOCA 7 72 CJCHA 50 70 JSSCB 1 61 JCPSA 48 71 JSSCB 3 70 ACBCA 26 71 JSSCB 3 71 JSSCB 3 71 JSSCB 3 69 ACBCA 25 71 JSSCB 3 71 JSSCB 3 71 JSSCB 3 71 JSSCB 3 71 ACSAA 25 66 JPCSA 27 74 JINCA 36 74 JINCA 36 65 CCJDA 1965 67 ACACA 22 74 BUFCA 97 74 JINCA 36 74 JINCA 36 74 BUFCA 97 70 AMMIA 55 65 ACACA 18 1704 3648 454 5048 89 102 89 89 89 851 89 89 89 89 3337 997 1965 1965 611 639 3 1965 1965 3 90 874 R. D. SHANNON 763 T a b l e 6. Comparison o f mean octahedral M o 6 + - O distances with distortion Only structures with e.s.d.'s for M o - O distances of < 0.025 A were used. Compound Mo2(O2C6C14)6 Mo4On Mo4On Mo4On Mo4On Mo4Ot~ Mo4On orthorhombic monoclinic monoclinic orthorhombic orthorhombic monoclinic (ClsHnO2)2MoO2 (NH4)6[M07024].4H20 (NH4)6[MoTOz4]. 4 H 2 0 (NH4)6[M07024].4H20 LiMoO2AsO4 (NH4)6MoaO27.4H20 HgMoO4 (NH4)6[MoTO24]. 4H20 (NH4)6[Mo7024]. 4H20 • (NH4)6[MoTO24]. 4 H 2 0 MoOa .2H20 MoOa. 2H20 MOO3.2H20 MOO3.2H20 (NHg)5[MoOa)5(PO4) (HPO4)]. 3H20 Naa(CrMo6024H~). 8HzO (NH4)6MoaO27.4H20 Na3CrMo6Oz4H6.8H20 (NH4)5[(MoO3)5(PO4) ( H P O 4 ) ] . 3 H 2 0 (NH4)dTeMo6024]. Te(OH)6.7HzO CoMoO4 (NHg)6MoaO27.4H20 MoO3 (NH4)6[Mo7024].4H20 K2{[MoO2(C204) (H20)]20} (NH4)6MoaO27.4H20 (NH4)s[(MoOz)s(PO4) (HPO4)]. 3H20 Na3CrMo6Oz4H6.8H20 (NH4)5[(MoOa)s(PO4) (HPO4)]. 3HzO MOO3.H20 (NH4)~[(MoO3)5(PO4) (HPO4)]. 3H20 (NH4)6[ Mo7024]. 4 H 2 0 (NH4)6[Mo7Oz4]. 4 H 2 0 " R (A) 1"919 1.944 1.946 1.937 1"951 1.911 1.945 1"952 1"962 1"972 1"960 1"967 1"960 1"965 1 "955 1"962 1.974 1.966 ] "961 1"957 1"953 1"970 1.976 1.976 1.976 1.974 1.981 1.991 1.972 1.981 1"976 1"976 1"974 1"982 1.986 1 "977 1-984 1 "991 1"991 2"008 Distortion zi = ((AR/R) z) x 10' 5 9 10 56 67 96 96 99 99 101 104 104 106 111 113 115 118 121 123 126 134 140 141 141 143 145 147 150 151 151 152 152 152 159 163 167 167 186 189 197 Reference 75 J A C S A 97 63 A R K E A 21 63 A R K E A 21 63 A R K E A 21 63 A R K E A 21 63 A R K E A 21 63 A R K E A 21 74 A C B C A 30 75 JCSIA 1975 75 JCSIA 1975 75 J C S I A 1975 70 A C S A A 24 74 A C B C A 30 73 A C B C A 29 75 JCSIA 1975 75 JCSIA 1975 68 J A C S A 90 72 ACBCA 28 . 72 A C B C A 28 72 A C B C A 28 72 A C B C A 28 74 JCSIA 1974 70 I N O C A 9 74 A C B C A 30 70 I N O C A 9 74 JCSIA 1974 74 A C B C A 30 65 A C A C A 19 74 A C B C A 30 63 A R K E A 21 68 J A C S A 90 64 I N O C A 3 74 A C B C A 30 74 J C S I A 1974 70 I N O C A 9 74 J C S I A 1974 74 A C B C A 30 74 J C S I A 1974 75 JCSIA 1975 75 JCSIA 1975 2123 365 365 365 365 365 365 300 505 505 505 ' 3711 48 869 505 505 3275 2222 2222 2222 2222 941 2228 48 2228 941 2095 269 48 357 3275 1603 48 941 2228 941 1795 941 505 505 T a b l e 7. Variation o f mean M - O distance and effective ionic radius in octahedral environments as a function o f distortion Maximum Correlation G o o d n e s s Ion A x 104 N* Rot r0:l: m coefficient of fit ( x 103) M o ~+ 212 38 1.920 3-73 0.74 67 0.572 3.01 0-63 70 W e+ 122 7 1-925 3-30 0.75 19 0"565 3.28 0.66 24 V 5+ 576 16 1.887 2.62 0.98 8 N b s÷ 83 29 1.976 6.45 0.69 71 0.599 6.83 0.44 99 Ta 5+ 79 6 1.984 6.70 0.81 18 0.617 3.79 0-15 46 M n 3+ 71 15 1"994 7"08 0-82 30 0-624 6.15 0"54 50 Cu 2+ 316 26 2.085 3"99 0"82 77 Mg 2÷ 156 28 2.094 8.31 0.72 21 ' 0"728 8"86 0"77 • 18 Co 2+ 46 15 2"106 7"38 0"42 19 0"734 11 "70 0-70 16 Zn 2 + 71 16 2"099 7"70 0-64 21 0"736 8"20 0.74 16 Li ÷ 148 il 2"159 8"42 0"81 30 0"784 9.02 0-79 35 * N = n u m b e r of independent octahedra t R=Ro+mA. r = ro+ mzl. 764 R E V I S E D E F F E C T I V E I O N I C R A D I I IN H A L I D E S A N D C H A L C O G E N I D E S cupied sites relax toward their bonded cation neighbors. Therefore average distances should increase as the occupancy factor decreases. In general, partial occupancy seems to be more prevalent for cations which are weakly bonded to oxygen like Cu ÷, Ag ÷, alkali ions, and large alkaline earths. The most prominent examples are Li and Na compounds. Table 8 summarizes the existent data on some structures with partial cation occupancy. Fig. 6 shows the dependence of mean Li-O bond length on the degree of occupancy. Although the data are not extensive, it is apparent that mean distance increases as occupancy factor decreases. Extrapolation of the Li curve in Fig. 6 to zero occupancy, i.e. a tetrahedral Li vacancy, gives 2.10-2.15 A, which is close to the 2.11 A found for c~-LisGaO4 by Stewner & Hoppe (1971) and for fl eucryptite by Tscherry, Schulz & Laves (1972). Another example of the effects of partial occupancy can be found in the non-stoichiometric feldspar Sr0.a4Na0.03vq0.13All.69Si2.2908 reported by Grundy & Ito (1974). The mean Sr-O distance in this compound is 0.03 A greater than in the stoichiometric SrA1ESi2Oa (Chiari, Calleri, Bruno & Ribbe, 1975). The relation between mean distance and occupancy probably cannot be quantified precisely because the relaxation of oxygen ions will depend on the nature and number of other cation neighbors. 3. Effects of covalence Changes in interatomic distances due to covalence effects are anticipated in compounds with (1) anions less electronegative than fluorine or oxygen, i.e. chlor- ides, bromides, sulfides, selenides, etc. and (2) tetrahedral oxyanions such as the VO]- and AsO ]- groups. The effects of covalence show up as a lack of additivity of the radii and are generally referred to as 'covalent shortening'. (a) Halides and chalcogenides. Covalence effects can be observed by comparing the relative contraction of cation-anion distances in two different isotypic compounds as the anion becomes less electronegative, e.g. Fe 2+ in Fe2GeO4 and Fe2GeS4 vs Mg 2+ in Mg2GeO4 and Mg2GeS4. Covalence shortens both Fe-S and Mg-S bonds relative to Fe-O and Mg-O bonds, but because of the greater electronegativity of Fe 2+ (1.8) compared to Mg 2+ (1.2), the Fe-S bonds are shortened to a greater extent. Thus a 'covalency contraction' parameter (Shannon & Vincent, 1974) can be defined: d(Fe-X) a Ra= d(Mg_X)3 where d ( F e - X ) = m e a n Fe-X distance. A similar parameter Rv= V(Fer, Xn) V(MgmXn) compares the volume of an Fe 2+ compound with that of an isotypic Mg 2+ compound. To see the effects of covalence on the Fe-X distance relative to the Mg-X distance, the ratio Rv or Rd may be plotted against the difference in electronegativity of the Fe-X bond, AZFe-x. Such schematic Rv-A Z plots are shown in Fig. 7. The reference ions for Cd 2÷ and In 3+ are Ca 2+ and Sc3+ respectively. Such plots usually show a strong Table 8. Mean distances in structures with partially occupied cation sites Compound (a) IVLi+ Typical LiAISiO4 (fl eucryptite) Occupancy factor Reference Table 1 73 AMMIA 72 ZKKKA 68 ZKKKA. 69 ZKKKA 72 ZKKKA 70 ZKKKA 68 ZKKKA 71 ACBCA 72 ZKKKA 58 135 126 130 135 132 127 27 135 681 175 46 420 161 118 327 616 175 59 9 59 25 127 9 27 280 345 280 1503 94 345 1826 LiA1Si206 II (fl spodumene) 0"50 LiA1SiO4 (fl eucryptite) Li2Al2Si3Olo LiAISi206 III ~-LisGaO4 LiAISiO4 0-50 0-40 0.33 0.00 0.00 1.97 2.020 (4) 2.025 (7) 2-08 (4) 2-085 (9) 2.056 (2) 2.064 (4) 2.068 (5) 2.11 2.11 1.00 0.91 0.82 0.70 0.50 0"35 0.29 0.25 2.42 2.533 (6) 2.74 2.723 (6) 2.600 (9) 2"839 (I) 2.65 2.88 Table 1 74 AMMIA 74 JSSCB 74 AMMIA 69 ACBCA 68 ZKKKA 74 JSSCB 71 ACBCA 1.00 0"44 0.33 0.22 2.50 2"64 2.75 2.83 Table 1 74 JSSCB 74 JSSCB 72 JSSCB (b) VINa+ Typical Na2Fe2AI(PO4)3 (wyllieite) NaSbO3 Na2Fe2AI(PO4)3 (wyllieite) NaA1Si3Oa (high albite) NaAlnOt7 (fl-A1203) NaSbO3 Na2.58A121.81034 (fl-A1203) (c) ViAg÷ Typical AgSbO3 AgSbO3 Agz.4A122034.2. 1"00 1.00 R 345 345 60 R. z.15 / , , , i | 2'10I 2.05~- IL~ D. S H A N N O N i i VACANCY IN ,, UsC.-aO 4 AND .8 EUCRYPTITE e LiALSi206 T (~ SPODUMENE) l LiAISi04~ ,,~ ~LiAISiz06]I[ (~ EUCRYPTITE) = UzAIzSisO~o ~UAtSi04 2"00i (,8 EUCRYPTITE) e~TYPICAL i .95F-Li+-O DISTANCE I'S°/~- i I t 1.0 .9 .8 .7 I I 5 I , I .2 I , 0 OCCUPANCY Fig. 6. Mean Li÷-O bond length us partial occupancy. 1.20 | I I I UNFILLED "d" SHELL 2+,Mn2+, C02+,N j2+ 1.10 1.00 FI LLED "d" SHELL Zn2+ Cd2+ in3+ ~ - ~ Rv or Rd 0.90 0.80 FLUORIDES OXIDES 2.5 CHLORIDES SULFIDES/SELENIDESJ BROMIDES | /IODIDES 1.5 2.0 1.0 0.5 0.0 L~ Fig. 7. Covalency contraction parameter, Ro or Ra, vs ,dZ for filled and unfilled d shell cations. 1.30 t i i i i ,2o-C'-.": ~_~" eNa-H LIO eLi-H eLiBaH3 1.00 • Mg-H 0.90 Rv aSi-H f ~ 0.80 aAt-H 0.70 B-H o D P-H a As-H 0.60 aC-H O.5C I 0.,~ l~ ,Io & oo' -~.s N-Ho -o9 z~x Fig. 8. Covalency contraction parameter, R, or Rd, vs AX for hydrides. Solid circles represent ratios of cell volumes of isotypic compounds. Squares represent ratios of the cubed M-H distances to the cubed M-F distances. 765 dependence of Rv on ZIZ. For Fe2+-Mg 2+ the Fe 2+ fluoride volumes are ~ 1 1 0 % of the corresponding* Mg 2+ fluoride volumes whereas the Fe 2÷ sulfide volumes are ~ 9 6 % of the corresponding Mg z+ sulfide volumes. Plots for the cations with filled 'd' shells show a markedly smaller dependence on zlg. This appears to be due to the difference in covalence of hybrid orbitals formed from metal 'd' orbitals vs metal 's-p' orbitals. These relations show that effective ionic radii derived primarily from oxides are not strictly applicable to fluorides - note the change in Rv for Fe 2+, Co 2+, Ni 2+, and Mn 2+ from fluorides to oxides. This effect is particularly noticeable in R~-ZIX plots for the pairs Cu+-Li ÷ and Ag+-Na ÷ (Shannon & Gumerman, 1975). The Cu+-Li + and Ag+-Na ÷ plots are very steep, e.g. the volume of AgF is 120 % of the volume of NaF, whereas the volume of Ag2Se is only 72 % of the volume of Na2Se. Although most of this change arises from covalency, double repulsion effects present in the Li and Na halides described by Pauling (1960) may also play a role. Covalence effects are useful in explaining certain differences between the effective ionic radii of Table 1 and the ionic radii of Pauling (1927) and Ahrens (1952). Pauling's radii for Cu ÷ (0.96 A) and Ag ÷ (1.26/~) are considerably larger than those in Table 1 (0.77 and 1.15 A respectively). Since these radii were derived from comparison of alkali halide distances, using an equation relating effective nuclear charge and screening constants (Pauling, 1927), they are valid in primarily ionic crystals. The smaller radii in Table 1 are applicable in the more covalent oxides. Extrapolation of R vs ZIX curves such as in Fig. 7 leads to values of 0.91 /~ and 1.23 A for fluorides, which are close to Pauling's ionic values. A final example of covalence effects concerns M + - H - distances. According to Gibb (1962), the radius of the hydride ion is slightly larger than the radius of the fluoride ion. To rationalize the behavior of the hydride ion, the M - H bond has been treated as covalent. Therefore, it is useful to make R~ vs AZ plots similar to those just discussed for Fe 2+, Cu +, etc. In this case, the reference ion is F - and volumes of certain hydrides are compared to those of isotypic fluorides. The results of this analysis are shown in Fig. 8. The solid circles represent volume ratios, R~ = V ( M = H , ) / V ( M m F , ) ; open squares represent ratios of typical distances Rd= d ( M - H ) 3 / d ( M - F ) 3. In the more ionic hydrides of Cs, Rb, K, and Na, hydride volumes are considerably larger than those of the fluorides. For the Li and Mg compounds, hydride and fluoride volumes are approximately equal, whereas the more covalent hydrides have increasingly smaller relative volumes than the corresponding fluorides. Fig. 8 partly explains the differences in reported radii. The Morris & Reed (1965) value of 1.53 A was derived essentially from the large alkali halides, while Gibb's value of 1.40 A was derived primarily from hydrides of the more electronegative 766 REVISED EFFECTIVE I O N I C R A D I I IN H A L I D E S A N D C H A L C O G E N I D E S metals such as: Sc, Ti, Y, Zr, HI', Nb, Ta, and Th. Because of this strong dependence of M - H distances on cation electronegativity, it does not seem very useful to quote a unique radius for H - . (b) Tetrahedral oxyanions. Lack of additivity also appears in most small tetrahedral groups and is particularly noticeable for the ions lVB3+, ~VFe3+, IVGe4+, tVA:+, IvVS+, IVS6+, XVSe6+, and IVflT+. The deviations in vanadates have been studied in detail (Shannon & Calvo, 1973b). Assuming that the V-O bond is strongly covalent, and that relatively electronegative cations such as Cu 2+, Ni 2+, and Co 2+ tend to remove electron density from the V-O bond, a V-O bond length increase in Cu, Ni, and Co vanadates is anticipated. Plots of mean radii (~) vs mean cation electronegativity (:~) show a marked slope with a gradual increase in ~(~vvs+) from vanadates of the alkali and alkaline earth ions to those of Cu, Ni, and Co. Similar plots for other ions, ps+, AsS+ (Shannon & Calvo, 1973b), B 3+, Si 4+, Se 6+ (Shannon, 1975), showed the same behavior. The statistical data on the tetrahedra of B3+, SIS+, Ge4+, p5+, ASS+, 56+, Se6+, Cr6+, M06+, W 6+, and C17+ have been summarized by Shannon (1975). The slopes of the i vs '2 plots were greatest for V 5+, Se 6+, and C17+, and least for Si4+. Although the evidence for covalence as the origin of these effects in the above systems is only indirect, this behavior is consistent with accepted ideas of 'covalent shortening' of bonds. The evidence for covalent shortening of lVFe3+-O bonds is more direct. Jeitschko, Sleight, McClellan & Weiher (1976) have found a good correlation between (1) the Fe M6ssbauer isomer shift and mean Fe-O distance and (2) ~ and mean Fe-O distance (R). Thus, in fl-NaFeO2/~= 1.86/~ and 3=0.18 mm s -1 relative to ~ Fe whereas in Bia(FeO4) (MOO4)2/~ = 1.909 A and = 0.282 mm s- 1. 4. Effects o f electron delocalization At a pressure of 6.5 kbar SmS (NaCI structure) undergoes a semiconductor to metal transition and a reduction in cell edge from 5.97 to 5.70 A. (Jayaraman, Narayanamurti, Bucher & Maines, 1970). The reduction in cell volume was attributed to a partial conversion of Sm 2+ to Sm 3+ ; some of the electrons presumably go into a conduction band. Electron delocalization effects can also be seen by comparing the volumes of the conducting V sulfides VS, VTSs, V3S4 and VsSs with the corresponding Cr sulfides which have localized 'd' electrons (de Vries & Jellinek, 1974). The V compounds have volumes ~ 5 % smaller than the corresponding chromium compounds. This does not agree with the relative sizes of V and Cr in oxides and fluorides, e.g. r(WV3+)=0"64 and r(WCr3+)=0.615 A. For the sulfides, this unit-cell volume anomaly is not simply attributable to metallic vs semiconducting behavior. While Cr3S4, Cr556, and Cr7Sa show a positive temperature dependence of resistivity typical of a metal, magnetic susceptibility measurements indicate Curie-Weiss behavior and therefore nearly localized electrons (van Bruggen, 1969). This is in contrast to the Pauli paramagnetic behavior of the corresponding V sulfides (de Vries & Haas, 1973) characteristic of delocalized electrons. Thus, in SmS and the sulfides of V metallic character accompanied by electron delocalization appears to be associated with reduced bond distances. A further example of delocalization effects occurs in the compound NaVS2 (Weigers, van der Meer, van Heinigen, Kloosterboer & Alberink, 1974). The molecular volume of Pauli paramagnetic NaVS2 1 (67.9 .&3) is significantly less than that of NaVS2 II (72.7 .&3). NaVS2 II is characterized by localized electrons (Jellinek, 1975) and its molecular volume is consistent with that of isotypic NaCrS2 (71.1 N3). If electron delocalization in oxides results in reduced metal-oxygen distances and thereby an effective increase in valence, radii derived for the ions Mo 4+, TC4+, Ru 4+, Rh 4+, W 4+, Re 4+, Os 4+, and Ir s+ from metallic oxides may not be reliable when applied to insulating oxides. Thus, radii obtained from distances in the metallic phases, e.g. RhOz, ReOz, and Cd2IrzO7, will be smaller than radii obtained from semiconducting or insulating compounds.* When both types of compounds have been studied, a significant difference in distances is generally found. The mean octahedral Re4+-O distance in insulating K4[Re202(C204)4]. 3H20 (Lis, 1975) of 2.021 (10)/~ (r=0.671 A) is greater than the estimated mean distance in metallic ReO2 of 1-99/~ (r=0.63/k). Knop & Carlow's (1974) value o f r = 0 . 6 6 2 A derived from cell volumes of the insulating Cs2ReF6 phases is consistent with the radius of Re 4+ from K4[Re202(CEO4)4].3H20. The ReS+-O distance in Nd4Re2Olt (Wilhelmi, Lagervall & Muller, 1970) of 1"987 (12) ,~ (r=0.607 A) is significantly greater than the distance in metallic Cd2Re207 (Sleight, 1975) of 1.93 (2)/k (r=0.55 A). The radii of 0"58 A derived from XeFsRuF6 and 0.60 A from XeFRuF6 (Bartlett, Gennis, Gibler, Morrell & Zalkin, 1973) are greater than the radius of 0.565 A derived from the r a - V plot for metallic Cd2Ru207. In contrast, however, the Mo 4+ radius of 0.64 /~ derived from insulating Li2MoF6 (Brunton, 1971) is not greatly different from the radius of 0.65 A derived from metallic MoO2 (Brandt & Skapski, 1967). Although there appears to be ample evidence to show that M - O bond distances in compounds with localized electrons are greater than M - O distances in compounds with delocalized electrons, the data are not yet sufficient to derive a reliable set of radii for semicon2ucting compounds4containing+Mo4+, Tc 4+ , Ru 4+ , Rh , W , Re , Os , and Ir . This will become possible as additional accurate structure refinements of fluorides, molecular inorganic compounds, and semiconducting oxides containing these ions become available. * This assumes that metallic character can be equated with delocalized electron behavior in these compounds. R. D. S H A N N O N I would like to acknowledge the help of F. Jellinek for providing unpublished data on NaVS2, F. C. Hawthorne for pointing out numerous structures containing partially occupied cation sites, O. Muller for several sources of radii of unusual ions, M. Fouassier for unpublished data on K4MO4 compounds, I. D. Brown for unpublished bond length-bond strength curves, and P. S. Gumerman for assistance with data collection. Structure data on rare earth halides and an analysis of the radii of divalent rare earths provided by H. Bg.rnighausen were especially valuable. I am particularly indebted to Ruth Shannon for the tabulation of data and proof reading. Finally, I would like to thank R. J. Bouchard, W. H. Baur, and H. B/irnighausen for critically reviewing the manuscript prior to publication. References AHRENS,L. H. (1952). Geochim. Cosmochim. Acta, 2,155-169. BARTLETT, N., GENNIS, M., GIBLER, D., MORRELL, B. & ZALKIN, A. (1973). Inorg. Chem. 12, 1717-1721. BAUR, W. H. (1972). Amer. Min. 57, 709-731. BAUR, W. H. (1974). Acta Cryst. B30, 1195-1215. BIRCHALL, T. & SLEIGHT, A. W. (1975). J. SolidState Chem. 13, 118-130. BONAMICO, M., DESSY, G., FARES, V. & SCARAMUZZA, L. (1974). J. Chem. Soc. Dalton, pp. 1258-1263. BRANDT, B. G. & SKAPSKI, A. C. (1967). Acta Chem. Scand. 21, 661-667. BROWN, I. D. (1975). Private communication. BROWN, I. D. & SHANNON, R. D. (1973). Acta Cryst. A29, 266-282. BRUGGEN, C. F. VAN (1969). Ph.D. Thesis, Univ. of Groningen. BRUNTON, G. (1971). Mater. Res. Bull. 6, 555-560. CHIARI, G., CALLERI, M., BRUNO, E. &. R1BBE,P. H. (1975). Amer. Min. 60, 111-119. Codens for Periodical Titles (1966). Vol. II. ASTM Data series DS23A, Philadelphia. DEMPSEY, M. J. & STRENS, R. G. J. (1975). Proc. NATO Conf. on Petrophysics, Newcastle-upon-Tyne, April 22-26. EVANS, H. T. JR (1951). Acta Cryst. 4, 377. FLYGARE, W. H. & HUGGINS, R. A. (1973). J. Phys. Chem. Solids, 34, 1199-1204. FUKUNAGA, O. & FUJITA, T. (1973). J. Solid State Chem. 8, 331-338. FUMI, F. G. & TosI, M. P. (1964). J. Phys. Chem. Solids, 25, 31-43. GELLER, S., WILLIAMS, H. J., ESPINOSA, G. P., SHERWOOD, R. C. &; GILLEO, M. A. (1963). Appl. Phys. Lett. 3, 21-22. GIBB, T. R.. P. (1962). Prog. Inorg. Chem. 3, 315-509. GREIS, O. & PETZEL,Z. (1974). Z. anorg, allgem. Chem. 403, 1-22. GRUNDY, H. D. & ITO, J. (1974). Amer. Min. 59, 1319-1326. HAWTHORNE, F. C. (1973). The Crystal Chemistry of the Clino-Amphiboles, Ph.D. Thesis, McMaster Univ. JAYARAMAN, A., NARAYANAMURTI, V., BUCHER, E. & MAINES, R. G. (1970). Phys. Rev. Lett. 25, 1430-1433. A C 32A - 2 View publication stats 767 JEITSCHKO, W., SLEIGHT, A. W., MCCLELLAN, W. R. & WEIHER, J. F. (1976). Acta Cryst. B32, 1163-1170. JELLINEK, F. (1975). Private communication. KA,LM~.N, A. (1971). Chem. Commun. pp. 1857-1859. KHAN, A. A. • BAUR, W. (1972). Acta Cryst. B28, 683-693. KNOP, O. & CARLOW, J. S. (1974). Canad. J. Chem. 52, 2175-2183. LIs, T. (1975). Acta Cryst. B31, 1594-1597. MCCARTHY, G. J. (1971). Mater. Res. Bull. 6, 31-40. MORRIS, D. F. C. & REED, G. L. (1965). J. Inorg. Nucl. Chem. 27, 1715-1717. MULLER, O. & ROY, R. (1974). Crystal Chemistry of NonMetallic Materials. 4. The Major Ternary Structural Families. New York: Springer-Verlag. PAULING, L. (1927). J. Amer. Chem. Soc. 49, 765-794. PAULING, L. (1960). The Nature of the Chemical Bond. Ithaca: Cornell Univ. Press. PETERSON, J. R. & CUNNINGHAM,B. B. (1967). Inorg. Nucl. Chem. Lett. 3, 327-336. PETERSON, J. R. & CUNNINGHAM, B. B. (1968). J. Inorg. Nucl. Chem. 30, 1775-1781. RIBBE, P. & GIBBS, G. V. (1971). Amer. Min. 56, 1155-1173. SHANNON, R. D. (1975). Proc. NATO Conf. on Petrophysics, Newcastle-upon-Tyne, April 22-26. SHANNON, R. D. & CALVO, C. (1973a). Acta Cryst. B29, 1338-1345. St-IANNON, R. D. & CALVO,C. (1973b). J. Solid State Chem. 6, 538-549. SHANNON, R. D. & GUMERMAN,P. S. (1975). J. Inorg. Nuel. Chem. 38, 699-703. SHANNON, R. D., GUMERMAN,P. S. & CHENAVAS,J. (1975). Amer. Min. 60, 714-716. SHANNON, R. D. & PREWITT, C. T. (1969). Acta Cryst. B25, 925-945. SHANNON, R. D. t~ VINCENT, H. (1974). Struct. Bond. (Berlin), 19, 1-43. SILVA, R. J., McDOWELL, W. J., KELLER, O. L. & TARRANT, J. R. (1974). Inorg. Chem. 13, 2233-2237. SLEIGHT, A. W. (1975). Private communication. SLEIGHT, A. W. & JONES, G. (1975). Acta Cryst. B31, 27482749. STEWART, D., KNOP, O., MEADS, R. & PARKER, W. (1973). Canad. J. Chem. 51, 1041-1049. STEWNER, F. & HOPPE, R. (1971). Acta Cryst. B27, 616--621. TILLMANNS, E. & BAUR, W. H. (1970). Acta Cryst. B26, 1645-1654. TILLMANNS, E., GEBERT, W. & BAUR, W. H. (1973). J. Solid State Chem. 7, 69-84. TSCHERRY, V., SCHULZ, H., & LAVES, F. (1972). Z. Kristalloaf. 135, 175-198. VRIES, A. B. DE t~ HAAS, C. (1973). J. Phys. Chem. Solids, 34, 651-659. VRIES, A. B. DE & JELLINEK, F. (1974). Rev. Chim. Miner. 11, 624-636. WEIGERS, G., VAN DER MEER, R., VAN HEININGEN, H., KLOOSTERBOER, H. & ALBERINK, A. (1974). Mater. Res. Bull. 9, 1261-1266. WILHELMI, K., LAGERVALL,E. t~ MULLER, O. (1970). Acta Chem. Scand. 24, 3406-3408. WOLFE, R; W. & NEWNHAM, R. E. (1969). J. Electrochem. Soc. 116, 832-835.