Characters of representations for molecular motions
Motion |
E |
C2.(z) |
C2.(y) |
C2.(x) |
i |
σ.(xy) |
σ.(xy) |
σ.(xy) |
Cartesian 3N |
60 |
0 |
0 |
0 |
0 |
12 |
8 |
0 |
Translation (x,y,z) |
3 |
-1 |
-1 |
-1 |
-3 |
1 |
1 |
1 |
Rotation (Rx,Ry,Rz) |
3 |
-1 |
-1 |
-1 |
3 |
-1 |
-1 |
-1 |
Vibration |
54 |
2 |
2 |
2 |
0 |
12 |
8 |
0 |
Decomposition to irreducible representations
Motion |
A1g |
B1g |
B2g |
B3g |
A1u |
B1u |
B2u |
B3u |
Total |
Cartesian 3N |
10 |
8 |
7 |
5 |
5 |
7 |
8 |
10 |
60 |
Translation (x,y,z) |
0 |
0 |
0 |
0 |
0 |
1 |
1 |
1 |
3 |
Rotation (Rx,Ry,Rz) |
0 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
3 |
Vibration |
10 |
7 |
6 |
4 |
5 |
6 |
7 |
9 |
54 |
Molecular parameter
Number of Atoms (N) |
20
|
Number of internal coordinates |
54
|
Number of independant internal coordinates |
10
|
Number of vibrational modes |
54
|
Force field analysis
Allowed / forbidden vibronational transitions
Operator |
A1g |
B1g |
B2g |
B3g |
A1u |
B1u |
B2u |
B3u |
Total |
Linear (IR) |
10 |
7 |
6 |
4 |
5 |
6 |
7 |
9 |
22 / 32 |
Quadratic (Raman) |
10 |
7 |
6 |
4 |
5 |
6 |
7 |
9 |
27 / 27 |
IR + Raman |
- - - - |
- - - - |
- - - - |
- - - - |
5 |
- - - - |
- - - - |
- - - - |
0* / 5 |
* Parity Mutual Exclusion Principle
Characters of force fields
(Symmetric powers of vibration representation)
Force field |
E |
C2.(z) |
C2.(y) |
C2.(x) |
i |
σ.(xy) |
σ.(xy) |
σ.(xy) |
linear |
54 |
2 |
2 |
2 |
0 |
12 |
8 |
0 |
quadratic |
1.485 |
29 |
29 |
29 |
27 |
99 |
59 |
27 |
cubic |
27.720 |
56 |
56 |
56 |
0 |
616 |
304 |
0 |
quartic |
395.010 |
434 |
434 |
434 |
378 |
3.234 |
1.434 |
378 |
quintic |
4.582.116 |
812 |
812 |
812 |
0 |
14.784 |
5.760 |
0 |
sextic |
45.057.474 |
4.466 |
4.466 |
4.466 |
3.654 |
60.830 |
21.542 |
3.654 |
Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field |
A1g |
B1g |
B2g |
B3g |
A1u |
B1u |
B2u |
B3u |
linear |
10 |
7 |
6 |
4 |
5 |
6 |
7 |
9 |
quadratic |
223 |
187 |
177 |
169 |
170 |
177 |
187 |
195 |
cubic |
3.601 |
3.497 |
3.419 |
3.343 |
3.371 |
3.419 |
3.497 |
3.573 |
quartic |
50.217 |
49.547 |
49.097 |
48.833 |
48.861 |
49.097 |
49.547 |
49.811 |
quintic |
575.637 |
573.791 |
571.535 |
570.095 |
570.501 |
571.535 |
573.791 |
575.231 |
sextic |
5.645.069 |
5.636.537 |
5.626.715 |
5.622.243 |
5.622.649 |
5.626.715 |
5.636.537 |
5.641.009 |
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 D
2h
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(A1g) ≤ i ≤ pos(B3u) |
..55. |
A1gA1g. | ..28. |
B1gB1g. | ..21. |
B2gB2g. | ..10. |
B3gB3g. | ..15. |
A1uA1u. | ..21. |
B1uB1u. | ..28. |
B2uB2u. | ..45. |
B3uB3u. | | |
| |
Subtotal: 223 / 8 / 8 |
Irrep combinations (i,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u) |
Subtotal: 0 / 0 / 28 |
Total: 223 / 8 / 36 |
Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(A1g) ≤ i ≤ pos(B3u) |
..220. |
A1gA1gA1g. | | |
| |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 220 / 1 / 8 |
Irrep combinations (i,i,j) (i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u) |
..280. |
A1gB1gB1g. | ..210. |
A1gB2gB2g. | ..100. |
A1gB3gB3g. | ..150. |
A1gA1uA1u. | ..210. |
A1gB1uB1u. | ..280. |
A1gB2uB2u. | ..450. |
A1gB3uB3u. | | |
| |
| |
Subtotal: 1.680 / 7 / 56 |
Irrep combinations (i,j,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(B3u) |
..168. |
B1gB2gB3g. | ..210. |
B1gA1uB1u. | ..441. |
B1gB2uB3u. | ..210. |
B2gA1uB2u. | ..324. |
B2gB1uB3u. | ..180. |
B3gA1uB3u. | ..168. |
B3gB1uB2u. | | |
| |
| |
Subtotal: 1.701 / 7 / 56 |
Total: 3.601 / 15 / 120 |
Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(A1g) ≤ i ≤ pos(B3u) |
..715. |
A1gA1gA1gA1g. | ..210. |
B1gB1gB1gB1g. | ..126. |
B2gB2gB2gB2g. | ..35. |
B3gB3gB3gB3g. | ..70. |
A1uA1uA1uA1u. | ..126. |
B1uB1uB1uB1u. | ..210. |
B2uB2uB2uB2u. | ..495. |
B3uB3uB3uB3u. | | |
| |
Subtotal: 1.987 / 8 / 8 |
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u) |
Subtotal: 0 / 0 / 56 |
Irrep combinations (i,i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(B3u) |
..1.540. |
A1gA1gB1gB1g. | ..1.155. |
A1gA1gB2gB2g. | ..550. |
A1gA1gB3gB3g. | ..825. |
A1gA1gA1uA1u. | ..1.155. |
A1gA1gB1uB1u. | ..1.540. |
A1gA1gB2uB2u. | ..2.475. |
A1gA1gB3uB3u. | ..588. |
B1gB1gB2gB2g. | ..280. |
B1gB1gB3gB3g. | ..420. |
B1gB1gA1uA1u. |
..588. |
B1gB1gB1uB1u. | ..784. |
B1gB1gB2uB2u. | ..1.260. |
B1gB1gB3uB3u. | ..210. |
B2gB2gB3gB3g. | ..315. |
B2gB2gA1uA1u. | ..441. |
B2gB2gB1uB1u. | ..588. |
B2gB2gB2uB2u. | ..945. |
B2gB2gB3uB3u. | ..150. |
B3gB3gA1uA1u. | ..210. |
B3gB3gB1uB1u. |
..280. |
B3gB3gB2uB2u. | ..450. |
B3gB3gB3uB3u. | ..315. |
A1uA1uB1uB1u. | ..420. |
A1uA1uB2uB2u. | ..675. |
A1uA1uB3uB3u. | ..588. |
B1uB1uB2uB2u. | ..945. |
B1uB1uB3uB3u. | ..1.260. |
B2uB2uB3uB3u. | | |
| |
Subtotal: 20.952 / 28 / 28 |
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(B3u) |
Subtotal: 0 / 0 / 168 |
Irrep combinations (i,j,k,l) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ l ≤ pos(B3u) |
..1.680. |
A1gB1gB2gB3g. | ..2.100. |
A1gB1gA1uB1u. | ..4.410. |
A1gB1gB2uB3u. | ..2.100. |
A1gB2gA1uB2u. | ..3.240. |
A1gB2gB1uB3u. | ..1.800. |
A1gB3gA1uB3u. | ..1.680. |
A1gB3gB1uB2u. | ..1.890. |
B1gB2gA1uB3u. | ..1.764. |
B1gB2gB1uB2u. | ..980. |
B1gB3gA1uB2u. |
..1.512. |
B1gB3gB1uB3u. | ..720. |
B2gB3gA1uB1u. | ..1.512. |
B2gB3gB2uB3u. | ..1.890. |
A1uB1uB2uB3u. | | |
| |
| |
| |
| |
| |
Subtotal: 27.278 / 14 / 70 |
Total: 50.217 / 50 / 330 |
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