Characters of representations for molecular motions
Motion |
E |
4C3 |
4(C3)2 |
3C2 |
i |
4(S6)5 |
4S6 |
3σh |
Cartesian 3N |
36 |
0 |
0 |
-4 |
0 |
0 |
0 |
8 |
Translation (x,y,z) |
3 |
0 |
0 |
-1 |
-3 |
0 |
0 |
1 |
Rotation (Rx,Ry,Rz) |
3 |
0 |
0 |
-1 |
3 |
0 |
0 |
-1 |
Vibration |
30 |
0 |
0 |
-2 |
0 |
0 |
0 |
8 |
Decomposition to irreducible representations
Motion |
Ag |
Eg*
|
Tg |
Au |
Eu*
|
Tu |
Total |
Cartesian 3N |
2 |
2 |
4 |
0 |
0 |
6 |
14 |
Translation (x,y,z) |
0 |
0 |
0 |
0 |
0 |
1 |
1 |
Rotation (Rx,Ry,Rz) |
0 |
0 |
1 |
0 |
0 |
0 |
1 |
Vibration |
2 |
2 |
3 |
0 |
0 |
5 |
12 |
Molecular parameter
Number of Atoms (N) |
12
|
Number of internal coordinates |
30
|
Number of independant internal coordinates |
2
|
Number of vibrational modes |
12
|
Force field analysis
Allowed / forbidden vibronational transitions
Operator |
Ag |
Eg*
|
Tg |
Au |
Eu*
|
Tu |
Total |
Linear (IR) |
2 |
2 |
3 |
0 |
0 |
5 |
5 / 7 |
Quadratic (Raman) |
2 |
2 |
3 |
0 |
0 |
5 |
7 / 5 |
IR + Raman |
- - - - |
- - - - |
- - - - |
0 |
0 |
- - - - |
0* / 0 |
* Parity Mutual Exclusion Principle
Characters of force fields
(Symmetric powers of vibration representation)
Force field |
E |
4C3 |
4(C3)2 |
3C2 |
i |
4(S6)5 |
4S6 |
3σh |
linear |
30 |
0 |
0 |
-2 |
0 |
0 |
0 |
8 |
quadratic |
465 |
0 |
0 |
17 |
15 |
0 |
0 |
47 |
cubic |
4.960 |
10 |
10 |
-32 |
0 |
0 |
0 |
208 |
quartic |
40.920 |
0 |
0 |
152 |
120 |
0 |
0 |
792 |
quintic |
278.256 |
0 |
0 |
-272 |
0 |
0 |
0 |
2.640 |
sextic |
1.623.160 |
55 |
55 |
952 |
680 |
5 |
5 |
8.008 |
Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field |
Ag |
Eg*
|
Tg |
Au |
Eu*
|
Tu |
linear |
2 |
2 |
3 |
0 |
0 |
5 |
quadratic |
28 |
28 |
52 |
15 |
15 |
60 |
cubic |
232 |
227 |
598 |
180 |
175 |
650 |
quartic |
1.828 |
1.828 |
5.012 |
1.620 |
1.620 |
5.180 |
quintic |
11.890 |
11.890 |
34.486 |
11.230 |
11.230 |
35.146 |
sextic |
68.800 |
68.770 |
201.860 |
66.738 |
66.713 |
203.692 |
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 T
h
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(Tu) |
..3. |
AgAg. | ..4. |
EgEg. | ..6. |
TgTg. | ..15. |
TuTu. | | |
| |
| |
| |
| |
| |
Subtotal: 28 / 4 / 6 |
Irrep combinations (i,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Tu) |
Subtotal: 0 / 0 / 15 |
Total: 28 / 4 / 21 |
Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(Ag) ≤ i ≤ pos(Tu) |
..4. |
AgAgAg. | ..8. |
EgEgEg. | ..11. |
TgTgTg. | | |
| |
| |
| |
| |
| |
| |
Subtotal: 23 / 3 / 6 |
Irrep combinations (i,i,j) (i,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Tu) |
..8. |
AgEgEg. | ..12. |
AgTgTg. | ..30. |
AgTuTu. | ..24. |
EgTgTg. | ..60. |
EgTuTu. | ..75. |
TgTuTu. | | |
| |
| |
| |
Subtotal: 209 / 6 / 30 |
Irrep combinations (i,j,k) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ pos(Tu) |
Subtotal: 0 / 0 / 20 |
Total: 232 / 9 / 56 |
Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(Ag) ≤ i ≤ pos(Tu) |
..5. |
AgAgAgAg. | ..9. |
EgEgEgEg. | ..51. |
TgTgTgTg. | ..295. |
TuTuTuTu. | | |
| |
| |
| |
| |
| |
Subtotal: 360 / 4 / 6 |
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Tu) |
..16. |
AgEgEgEg. | ..22. |
AgTgTgTg. | ..32. |
EgTgTgTg. | | |
| |
| |
| |
| |
| |
| |
Subtotal: 70 / 3 / 30 |
Irrep combinations (i,i,j,j) with indices: pos(Ag) ≤ i ≤ j ≤ pos(Tu) |
..12. |
AgAgEgEg. | ..18. |
AgAgTgTg. | ..45. |
AgAgTuTu. | ..60. |
EgEgTgTg. | ..150. |
EgEgTuTu. | ..495. |
TgTgTuTu. | | |
| |
| |
| |
Subtotal: 780 / 6 / 15 |
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ pos(Tu) |
..48. |
AgEgTgTg. | ..120. |
AgEgTuTu. | ..150. |
AgTgTuTu. | ..300. |
EgTgTuTu. | | |
| |
| |
| |
| |
| |
Subtotal: 618 / 4 / 60 |
Irrep combinations (i,j,k,l) with indices: pos(Ag) ≤ i ≤ j ≤ k ≤ l ≤ pos(Tu) |
Subtotal: 0 / 0 / 15 |
Total: 1.828 / 17 / 126 |
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Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement