Characters of representations for molecular motions
Motion |
E |
C3 |
(C3)2 |
i |
(S6)5 |
S6 |
Cartesian 3N |
36 |
0 |
0 |
0 |
0 |
0 |
Translation (x,y,z) |
3 |
0 |
0 |
-3 |
0 |
0 |
Rotation (Rx,Ry,Rz) |
3 |
0 |
0 |
3 |
0 |
0 |
Vibration |
30 |
0 |
0 |
0 |
0 |
0 |
Decomposition to irreducible representations
Motion |
Ag |
Eg*
|
Au |
Eu*
|
Total |
Cartesian 3N |
6 |
6 |
6 |
6 |
24 |
Translation (x,y,z) |
0 |
0 |
1 |
1 |
2 |
Rotation (Rx,Ry,Rz) |
1 |
1 |
0 |
0 |
2 |
Vibration |
5 |
5 |
5 |
5 |
20 |
Molecular parameter
Number of Atoms (N) |
12
|
Number of internal coordinates |
30
|
Number of independant internal coordinates |
5
|
Number of vibrational modes |
20
|
Force field analysis
Allowed / forbidden vibronational transitions
Operator |
Ag |
Eg*
|
Au |
Eu*
|
Total |
Linear (IR) |
5 |
5 |
5 |
5 |
10 / 10 |
Quadratic (Raman) |
5 |
5 |
5 |
5 |
10 / 10 |
IR + Raman |
- - - - |
- - - - |
- - - - |
- - - - |
0* / 0 |
* Parity Mutual Exclusion Principle
Characters of force fields
(Symmetric powers of vibration representation)
Force field |
E |
C3 |
(C3)2 |
i |
(S6)5 |
S6 |
linear |
30 |
0 |
0 |
0 |
0 |
0 |
quadratic |
465 |
0 |
0 |
15 |
0 |
0 |
cubic |
4.960 |
10 |
10 |
0 |
0 |
0 |
quartic |
40.920 |
0 |
0 |
120 |
0 |
0 |
quintic |
278.256 |
0 |
0 |
0 |
0 |
0 |
sextic |
1.623.160 |
55 |
55 |
680 |
5 |
5 |
Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field |
Ag |
Eg*
|
Au |
Eu*
|
linear |
5 |
5 |
5 |
5 |
quadratic |
80 |
80 |
75 |
75 |
cubic |
830 |
825 |
830 |
825 |
quartic |
6.840 |
6.840 |
6.800 |
6.800 |
quintic |
46.376 |
46.376 |
46.376 |
46.376 |
sextic |
270.660 |
270.630 |
270.430 |
270.405 |
Further Reading
- J.K.G. Watson, J. Mol. Spec. 41 229 (1972)
The Numbers of Structural Parameters and Potential Constants of Molecules
- X.F. Zhou, P. Pulay. J. Comp. Chem. 10 No. 7, 935-938 (1989)
Characters for Symmetric and Antisymmetric Higher Powers of Representations:
Application to the Number of Anharmonic Force Constants in Symmetrical Molecules
- F. Varga, L. Nemes, J.K.G. Watson. J. Phys. B: At. Mol. Opt. Phys. 10 No. 7, 5043-5048 (1996)
The number of anharmonic potential constants of the fullerenes C60 and C70
Contributions to nonvanishing force field constants
pos(X) : Position of irreducible representation (irrep) X in character table of S
6
Subtotal: <Number of nonvanishing force constants in subsection> / <number of nonzero irrep combinations in subsection> / <number of irrep combinations in subsection>
Total: <Number of nonvanishing force constants in force field> / <number of nonzero irrep combinations in force field> / <number of irrep combinations in force field>
Contributions to nonvanishing quadratic force field constants
Irrep combinations (i,i) with indices: pos(Ag) ≤ i ≤ pos(Eu) |
..15. |
AgAg. | ..25. |
EgEg. | ..15. |
AuAu. | ..25. |
EuEu. | | |
| |
| |
| |
| |
| |
Subtotal: 80 / 4 / 4 |
Irrep combinations (i,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Eu) |
Subtotal: 0 / 0 / 6 |
Total: 80 / 4 / 10 |
Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(Ag) ≤ i ≤ pos(Eu) |
..35. |
AgAgAg. | ..70. |
EgEgEg. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 105 / 2 / 4 |
Irrep combinations (i,i,j) (i,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Eu) |
..125. |
AgEgEg. | ..75. |
AgAuAu. | ..125. |
AgEuEu. | ..150. |
EgEuEu. | | |
| |
| |
| |
| |
| |
Subtotal: 475 / 4 / 12 |
Irrep combinations (i,j,k) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ pos(Eu) |
..250. |
EgAuEu. | | |
| |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 250 / 1 / 4 |
Total: 830 / 7 / 20 |
Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(Ag) ≤ i ≤ pos(Eu) |
..70. |
AgAgAgAg. | ..225. |
EgEgEgEg. | ..70. |
AuAuAuAu. | ..225. |
EuEuEuEu. | | |
| |
| |
| |
| |
| |
Subtotal: 590 / 4 / 4 |
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Eu) |
..350. |
AgEgEgEg. | ..350. |
AuEuEuEu. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 700 / 2 / 12 |
Irrep combinations (i,i,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Eu) |
..375. |
AgAgEgEg. | ..225. |
AgAgAuAu. | ..375. |
AgAgEuEu. | ..375. |
EgEgAuAu. | ..1.075. |
EgEgEuEu. | ..375. |
AuAuEuEu. | | |
| |
| |
| |
Subtotal: 2.800 / 6 / 6 |
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ pos(Eu) |
..750. |
EgEgAuEu. | ..750. |
AgEgEuEu. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 1.500 / 2 / 12 |
Irrep combinations (i,j,k,l) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ l ≤ pos(Eu) |
..1.250. |
AgEgAuEu. | | |
| |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 1.250 / 1 / 1 |
Total: 6.840 / 15 / 35 |
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Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement