Supplementary Material
Tin-Carbon Clusters and the Onset of Microscopic Level Immiscibility:
Experimental and Computational Study
J. Bernstein, A. Landau, E. Zemel and E. Kolodney
Schulich Faculty of Chemistry, Technion, Haifa 32000, Israel
Table of Contents
1. Additional Computational Details ………………………………...…………….....2
2. Additional Computational Results……………….....…..……………...….…….....3
1
1. Additional Computational Details
Born-Oppenheimer molecular-dynamics (BOMD) was used as a global minima search method
for identifying minimum energy structures and isomers of tin carbide clusters presented in the
paper. Here we show a BOMD scan, resulting in the detection of two Sn3C4 isomers (CCSD(T) single
point energies based on DFT optimized structures).
BOMD - B3P86/cc-pVTZ Sn4C3 (singlet)
1.4
b
Relative Energy, eV
1.2
1.0
0.8
0.6
0.4
0.2
ΔE=0 eV
0.0
ΔE=0.16 eV
-0.2
0
1000
2000
3000
4000
5000
Time Steps
Figure S1: BOMD trajectory carried out for neutral Sn3C4. Total duration time of the trajectory (5000 time
steps) is about 2 psec. The DFT optimized ground state isomers are shown. The energy difference (ΔE)
between two isomers values are calculated using CCSD(T). ΔE’s are given relative to the energy of the
most stable structure (deepest minimum) in the BOMD scan.
2
2. Additional Computational Results
2.1 Dissociation energies of the cationic clusters: Sn2Cn+ (n=1-7)
Dissociation
energies
DE(n)
for
several
possible
dissociation
channels
(e.g.
DE = E(SnC+ + Sn) - E(Sn C+ ) for Sn atom emission) of the cations are presented in Fig. S2. Shown
n
2 n
are DE values for emission of Sn (Sn2Cn+  Sn2Cn+ + Sn), SnC (Sn2Cn+  SnCn-1+ + SnC), C
(Sn2Cn+  Sn2Cn-1+ + C) and C2 (Sn2Cn+  Sn2Cn-2+ + C2) emission processes. The Sn emission
process exhibits a relatively flat DE(n) dependence with weak alternations for n>4. The
dissociation energies vary only slightly between 4.6 to 5.4 eV. This is the lowest energy channel
and is relatively insensitive to the number of carbon atoms in the cluster. Emission energies of SnC
from the higher cluster ions in this series show rather weak alternations between 8.8 and 7.5 eV
which are too small to be observed experimentally. Due to kinetic considerations, the C and C2
emission processes are much less probable and therefore will not be discussed.
Sn2C+n (n=1-8)
7
a
+
+
Sn2Cn ---> SnCn + Sn
6
5
4
12
+
+
b
Sn2Cn ---> Sn2Cn-1 + SnC
c
Sn2Cn ---> Sn2Cn-1 + C
d
Sn2Cn ---> Sn2Cn-2 + C2
9
DE, eV
6
3
9
8
7
6
5
4
8
+
+
+
+
7
6
1
2
3
4
5
6
7
8
n
Figure S2: CCSD(T) calculated dissociation energies of the cations Sn2Cn+ (n=1-8) as a function of the
number of carbon atoms n for different dissociation channels. (a) Emission of a Sn atom. (b) Emission of a
SnC unit. (c) Emission of a C atom. (d) Emission of a C2 unit. Pronounced alternations are observed mainly
for the C emission channel. Note the different energy scales for the different channels. The lowest
3
dissociation energies is associated with the Sn emission channel while the highest ones are due to SnC
emission.
2.2 Dissociation energies of the cationic clusters: Sn3Cn+ (n=1-5)
Dissociation energies DE(n) for Sn (Sn3Cn+  Sn3Cn+ + Sn), SnC (Sn3Cn+  SnCn-1+ + SnC),
C (Sn3Cn+  Sn3Cn-1+ + C) and C2 (Sn3Cn+  Sn3Cn-2+ + C2) emission processes are presented in
Fig.S3 . The general trend in this series is the rather weak variation in both ionization and
dissociation energies. The Sn emission is the lowest energy channel (4.6 to 2.9 eV) and therefore
probably the dominant one. The gradual DE(n) decrease is in agreement with experiment. The
emission of SnC is less favored, with values between 5.9 and 8.0 eV. The higher stability of Sn3C2+
is not manifested in the spectrum. Although the emission energies of C and C2 are comparable
with that of SnC the process is unlikely due to kinetic restrictions.
Sn3C+n (n=1-5)
6
+
a
+
Sn3Cn ---> Sn2Cn + Sn
4
2
10
b
+
8
DE, eV
+
Sn3Cn ---> Sn2Cn-1 + SnC
6
9
8
+
+
c
Sn3Cn ---> Sn3Cn-1 + C
d
Sn3Cn ---> Sn3Cn-2 + C2
7
6
5
9
8
+
+
7
6
5
1
2
3
4
5
n
Figure S3: CCSD(T) calculated dissociation energies of the cations Sn3Cn+ (n=1-5) as a function of the
number of carbon atoms n for different dissociation channels. (a) Emission of a Sn atom. (b) Emission of a
SnC unit. (c) Emission of a C atom. (d) Emission of a C2 unit. Variations of dissociation energies with n
are rather weak for all channels. Note the different energy scales for the different channels. The lowest
dissociation energies are associated with the Sn emission channel (DE=2.9-4.6 eV) while the highest ones
are due to C2 emission (DE=5.7-7.0 eV).
4
2.3 Dissociation energies of the cationic clusters: Sn4Cn+ (n=1-4)
Dissociation energies DE(n) for Sn (Sn4Cn+  Sn4Cn+ + Sn), SnC (Sn4Cn+  SnCn-1+ + SnC),
C (Sn4Cn+  Sn4Cn-1+ + C) and C2 (Sn4Cn+  Sn3Cn-2+ + C2) emission processes are presenred in
Fig. S4. The lowest energy (most probable) Sn emission channel exhibits a relatively flat DE(n)
dependence (3.3 to 3.7 eV). The SnC, C, and C2 emission processes are similar in energies and
vary from 5.2 to 7.3 eV. Comparing experiment with computational results in this series is difficult
due to the weak signals and the fact that the number of isomers is large.
Sn4C+n (n=1-4)
6
+
+
a
Sn4Cn ---> Sn3Cn + Sn
b
Sn4Cn ---> Sn3Cn-1 + SnC
c
Sn4Cn ---> Sn4Cn-1 + C
d
Sn4Cn ---> Sn4Cn-2 + C2
4
2
10
+
DE, eV
8
+
6
9
+
+
7
5
9
+
+
7
5
1
2
3
4
n
Figure S4: CCSD(T) calculated dissociation energies of the cations Sn4Cn+ (n=1-4) for different
dissociation channels. (a) Emission of a Sn atom. (b) Emission of a SnC unit. (c) Emission of a C atom. (d)
Emission of a C2 unit. Note the different energy scales for the different channels. The lowest dissociation
energies are associated with the Sn emission channel (DE=3.3-3.7 eV) while the highest ones are due to
SnC emission (DE=5.8-7.1 eV).
5
2.4 Ionization and dissociation energies of the neutral clusters : Sn2Cn (n=1-8)
Sn2Cn (n=1-8)
9
+
Sn2Cn ---> SnCn + e-
a
8
7
VIE
AIE
6
7
b
Sn2Cn ---> SnCn + Sn
c
Sn2Cn ---> Sn2Cn-1 + SnC
d
Sn2Cn ---> Sn2Cn-1 + C
e
Sn2Cn ---> Sn2Cn-2 + C2
6
5
4
3
DE, eV
2
12
9
6
3
9
8
7
6
5
4
8
7
6
5
4
1
2
3
4
5
6
7
8
n
Figure S5: CCSD(T) calculated adiabatic ionization, (AIE, solid line), vertical ionization (VIE, dashed
line), and dissociation energies of neutral clusters Sn2Cn (n=1-8) for different dissociation channels. (a)
Ionization energy. (b) Emission of a Sn atom. (c) Emission of a SnC unit. (d) Emission of a C atom. (e)
Emission of a C2 unit. Note the different energy scales for the different channels. The lowest dissociation
energies are associated with the Sn emission channel (ΔE=3.0-5.0 eV) while the highest ones are due to
SnC emission (ΔE=5.0-8.3 eV).
6
2.5 Ionization and dissociation energies of the neutral clusters: Sn3Cn (n=1-5)
Sn3Cn (n=1-5)
9
+
a
Sn3Cn ---> Sn3Cn + e-
8
7
6
VIE
AIE
5
6
b
Sn3Cn ---> Sn2Cn + Sn
c
Sn3Cn ---> Sn2Cn-1 + SnC
d
Sn3Cn ---> Sn3Cn-1 + C
e
Sn3Cn ---> Sn3Cn-2 + C2
4
DE, eV
2
10
8
6
9
8
7
6
5
9
8
7
6
5
1
2
3
4
5
n
Figure S6: CCSD(T) calculated adiabatic ionization, (AIE, solid line), vertical ionization (VIE, dashed
line), and dissociation energies of neutral clusters Sn3Cn (n=1-5) for different dissociation channels. (a)
Ionization energy. (b) Emission of a Sn atom. (c) Emission of a SnC unit. (d) Emission of a C atom. (e)
Emission of a C2 unit. Note the different energy scales for the different channels. The lowest dissociation
energies are associated with the Sn emission channel (ΔE=2.7-3.3 eV) while the highest ones are due to C
emission (ΔE=5.8-6.1 eV).
7
2.6 Ionization and dissociation energies of the neutral clusters: Sn4Cn (n=1-4)
Sn4Cn (n=1-4)
9
+
Sn4Cn ---> Sn4Cn + e-
a
8
7
6
VIE
AIE
5
6
Sn4Cn ---> Sn3Cn + Sn
b
4
DE, eV
2
10
c
Sn4Cn ---> Sn3Cn-1 + SnC
8
6
10
9
8
7
6
5
4
10
9
8
7
6
5
4
d
Sn4Cn ---> Sn4Cn-1 + C
e
Sn4Cn ---> Sn4Cn-2 + C2
1
2
3
4
n
Figure S7: CCSD(T) calculated adiabatic ionization, (AIE, solid line), vertical ionization (VIE, dashed
line), and dissociation energies of neutral clusters Sn4Cn (n=1-4) for different dissociation channels. (a)
Ionization energy. (b) Emission of a Sn atom. (c) Emission of a SnC unit. (d) Emission of a C atom. (e)
Emission of a C2 unit. Note the different energy scales for the different channels. The lowest dissociation
energies are associated with the Sn emission channel (ΔE=2.9-4.3 eV) while the highest ones are due to
SnC emission (ΔE=5.8-7.2 eV).
8