Reduction formula for point group Cs
Characters for molecular motions
| Motion |
E |
 h |
| Cartesian 3N |
12 |
4 |
| Translation (x,y,z) |
3 |
1 |
| Rotation (Rx,Ry)* |
2 |
0 |
| Vibration |
7 |
3 |
* Linear molecule
Decomposition into Irreducible representations
| Motion |
A' |
A'' |
Total |
| Cartesian 3N |
8 |
4 |
12 |
| Translation (x,y,z) |
2 |
1 |
3 |
| Rotation (Rx,Ry)* |
1 |
1 |
2 |
| Vibration |
5 |
2 |
7 |
* Linear molecule
Molecule Parameter
| Number of Atoms (N) |
4 |
| Number of internal coordinates |
7 |
| Number of independant internal coordinates |
5 |
| Number of vibrational modes |
7 |
Force field analysis
Allowed / forbidden vibronational transitions
| Operator |
A' |
A'' |
Total |
| Linear (IR) |
5 |
2 |
7 / 0 |
| Quadratic (Raman) |
5 |
2 |
7 / 0 |
| IR + Raman |
5 |
2 |
7 / 0 |
Characters of symmetric powers for vibration representation
| Force field |
Tensor
Order |
E |
h |
| linear |
1 |
7 |
3 |
| quadratic |
2 |
28 |
8 |
| cubic |
3 |
84 |
16 |
| quartic |
4 |
210 |
30 |
| quintic |
5 |
462 |
50 |
| sextic |
6 |
924 |
80 |
Decomposition into Irreducible representations
Number of nonvanshing force constants
| Force field |
Tensor
Order |
A' |
A'' |
| linear |
1 |
5 |
2 |
| quadratic |
2 |
18 |
10 |
| cubic |
3 |
50 |
34 |
| quartic |
4 |
120 |
90 |
| quintic |
5 |
256 |
206 |
| sextic |
6 |
502 |
422 |
Literature
- 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
Last update November, 13th 2023 by A. Gelessus, Impressum, Datenschutzerklärung/DataPrivacyStatement