File: postpubli02.doc
M.X. Fernandes, P. Bernadó, M. Pons and J. García de la Torre, “An analytical solution
to the problem of orientation of rigid particles by planar obstacles. Application to
membrane systems and to the calculation of dipolar couplings in NMR spectroscopy”,
Journal of the American Chemical Society, 123, 12037-12047 (2001).
Post-publication Notes
- - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - February, 2002
A minor bug has been found in version 1.a. Due to a small error in a numerical constant,
the calculated RDCs were (in absolute value) about 10% higher than the correct values
(This error did not affect the results appeared in our JACS 2001 article, which were
calculated with the correct constant). This bug has been fixed in the next version, 1.c.
- - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - November, 2001
An erratum has been found in our paper. Equations 75 in the Appendix (Supplemental
material) contained an error; they should read:

 A  2A
a
 zz

 2 
 Axx   Aa 1  R 
 3 

 2 

 Ayy   Aa 1  3 R 

(75)
with the correct numerical factor 3/2 (rather than 2/3). This error has propagated to the
equation (eq. 27 in the article, eq. 76 in the Appendix) that gives the generalized degree
of order,  , in terms of the axial component, Aa, and the rhombicity, R, of the
alignment tensor. The correct result is
and

2 2
4 2
4 2
4 2
6 Aa 1 
R   2 Aa 1 
R  Azz 1 
R
3
27
27
 27 
(27),(76)
with the correct numerical factor ¾ (rather than 4/27). Also, the numerical results
in the original Table 1 of the Appendix are incorrect. The correct values are:
Table 1. Contribution of the rhombicity to the generalized degree of order
R
1
4 2
R
27
0.2
0.3
0.4
0.5
0.6
1.003
1.007
1.012
1.018
1.026
Fortunately equation 27 is not used in the calculation, and therefore none of the results
reported in the article is affected. Equation 27 was formulated just to show that the
effect of rhombicity on the degree of order is rather small. The correct values, although
they are slightly higher than those previously reported, still lead to this conclusion: the
effect of the usual values of rhombicity on  is of a few percent.
We are grateful to Dr. J. Santoro for bringing this error to our attention.