Characters of representations for molecular motions
Motion |
E |
2C3 |
3C'2 |
i |
2S6 |
3σd |
Cartesian 3N |
21 |
0 |
-1 |
-3 |
0 |
3 |
Translation (x,y,z) |
3 |
0 |
-1 |
-3 |
0 |
1 |
Rotation (Rx,Ry,Rz) |
3 |
0 |
-1 |
3 |
0 |
-1 |
Vibration |
15 |
0 |
1 |
-3 |
0 |
3 |
Decomposition to irreducible representations
Motion |
A1g |
A2g |
Eg |
A1u |
A2u |
Eu |
Total |
Cartesian 3N |
2 |
1 |
3 |
1 |
3 |
4 |
14 |
Translation (x,y,z) |
0 |
0 |
0 |
0 |
1 |
1 |
2 |
Rotation (Rx,Ry,Rz) |
0 |
1 |
1 |
0 |
0 |
0 |
2 |
Vibration |
2 |
0 |
2 |
1 |
2 |
3 |
10 |
Molecular parameter
Number of Atoms (N) |
7
|
Number of internal coordinates |
15
|
Number of independant internal coordinates |
2
|
Number of vibrational modes |
10
|
Force field analysis
Allowed / forbidden vibronational transitions
Operator |
A1g |
A2g |
Eg |
A1u |
A2u |
Eu |
Total |
Linear (IR) |
2 |
0 |
2 |
1 |
2 |
3 |
5 / 5 |
Quadratic (Raman) |
2 |
0 |
2 |
1 |
2 |
3 |
4 / 6 |
IR + Raman |
- - - - |
0 |
- - - - |
1 |
- - - - |
- - - - |
0* / 1 |
* Parity Mutual Exclusion Principle
Characters of force fields
(Symmetric powers of vibration representation)
Force field |
E |
2C3 |
3C'2 |
i |
2S6 |
3σd |
linear |
15 |
0 |
1 |
-3 |
0 |
3 |
quadratic |
120 |
0 |
8 |
12 |
0 |
12 |
cubic |
680 |
5 |
8 |
-28 |
-1 |
28 |
quartic |
3.060 |
0 |
36 |
72 |
0 |
72 |
quintic |
11.628 |
0 |
36 |
-144 |
0 |
144 |
sextic |
38.760 |
15 |
120 |
300 |
3 |
300 |
Decomposition to irreducible representations
Column with number of nonvanshing force constants highlighted
Force field |
A1g |
A2g |
Eg |
A1u |
A2u |
Eu |
linear |
2 |
0 |
2 |
1 |
2 |
3 |
quadratic |
16 |
6 |
22 |
8 |
10 |
18 |
cubic |
64 |
46 |
108 |
55 |
65 |
117 |
quartic |
288 |
234 |
522 |
240 |
258 |
498 |
quintic |
1.002 |
912 |
1.914 |
954 |
1.008 |
1.962 |
sextic |
3.363 |
3.153 |
6.507 |
3.162 |
3.252 |
6.408 |
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
3d
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(Eu) |
..3. |
A1gA1g. | ..3. |
EgEg. | ..1. |
A1uA1u. | ..3. |
A2uA2u. | ..6. |
EuEu. | | |
| |
| |
| |
| |
Subtotal: 16 / 5 / 6 |
Irrep combinations (i,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(Eu) |
Subtotal: 0 / 0 / 15 |
Total: 16 / 5 / 21 |
Contributions to nonvanishing cubic force field constants
Irrep combinations (i,i,i) with indices: pos(A1g) ≤ i ≤ pos(Eu) |
..4. |
A1gA1gA1g. | ..4. |
EgEgEg. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 8 / 2 / 6 |
Irrep combinations (i,i,j) (i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(Eu) |
..6. |
A1gEgEg. | ..2. |
A1gA1uA1u. | ..6. |
A1gA2uA2u. | ..12. |
A1gEuEu. | ..12. |
EgEuEu. | | |
| |
| |
| |
| |
Subtotal: 38 / 5 / 30 |
Irrep combinations (i,j,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(Eu) |
..6. |
EgA1uEu. | ..12. |
EgA2uEu. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 18 / 2 / 20 |
Total: 64 / 9 / 56 |
Contributions to nonvanishing quartic force field constants
Irrep combinations (i,i,i,i) with indices: pos(A1g) ≤ i ≤ pos(Eu) |
..5. |
A1gA1gA1gA1g. | ..6. |
EgEgEgEg. | ..1. |
A1uA1uA1uA1u. | ..5. |
A2uA2uA2uA2u. | ..21. |
EuEuEuEu. | | |
| |
| |
| |
| |
Subtotal: 38 / 5 / 6 |
Irrep combinations (i,i,i,j) (i,j,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(Eu) |
..8. |
A1gEgEgEg. | ..10. |
A1uEuEuEu. | ..20. |
A2uEuEuEu. | | |
| |
| |
| |
| |
| |
| |
Subtotal: 38 / 3 / 30 |
Irrep combinations (i,i,j,j) with indices: pos(A1g) ≤ i ≤ j ≤ pos(Eu) |
..9. |
A1gA1gEgEg. | ..3. |
A1gA1gA1uA1u. | ..9. |
A1gA1gA2uA2u. | ..18. |
A1gA1gEuEu. | ..3. |
EgEgA1uA1u. | ..9. |
EgEgA2uA2u. | ..39. |
EgEgEuEu. | ..3. |
A1uA1uA2uA2u. | ..6. |
A1uA1uEuEu. | ..18. |
A2uA2uEuEu. |
Subtotal: 117 / 10 / 15 |
Irrep combinations (i,i,j,k) (i,j,j,k) (i,j,k,k) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ pos(Eu) |
..2. |
EgEgA1uA2u. | ..9. |
EgEgA1uEu. | ..18. |
EgEgA2uEu. | ..24. |
A1gEgEuEu. | ..6. |
A1uA2uEuEu. | | |
| |
| |
| |
| |
Subtotal: 59 / 5 / 60 |
Irrep combinations (i,j,k,l) with indices: pos(A1g) ≤ i ≤ j ≤ k ≤ l ≤ pos(Eu) |
..12. |
A1gEgA1uEu. | ..24. |
A1gEgA2uEu. | | |
| |
| |
| |
| |
| |
| |
| |
Subtotal: 36 / 2 / 15 |
Total: 288 / 25 / 126 |
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Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement