Reduction formula for point group C2h
Characters for molecular motions
Motion |
E |
C2 (z) |
i |
h |
Cartesian 3N |
12 |
0 |
0 |
4 |
Translation (x,y,z) |
3 |
-1 |
-3 |
1 |
Rotation (Rx,Ry,Rz) |
3 |
-1 |
3 |
-1 |
Vibration |
6 |
2 |
0 |
4 |
Decomposition into Irreducible representations
Motion |
Ag |
Bg |
Au |
Bu |
Total |
Cartesian 3N |
4 |
2 |
2 |
4 |
12 |
Translation (x,y,z) |
0 |
0 |
1 |
2 |
3 |
Rotation (Rx,Ry,Rz) |
1 |
2 |
0 |
0 |
3 |
Vibration |
3 |
0 |
1 |
2 |
6 |
Molecule Parameter
Number of Atoms (N) |
4 |
Number of internal coordinates |
6 |
Number of independant internal coordinates |
3 |
Number of vibrational modes |
6 |
Force field analysis
Allowed / forbidden vibronational transitions
Operator |
Ag |
Bg |
Au |
Bu |
Total |
Linear (IR) |
3 |
0 |
1 |
2 |
3 / 3 |
Quadratic (Raman) |
3 |
0 |
1 |
2 |
3 / 3 |
IR + Raman |
- |
- |
- |
- |
0* / 0 |
* Center of inversion: Mutual Exclusion Principle
Characters of symmetric powers for vibration representation
Force field |
Tensor Order |
E |
C2 (z) |
i |
h |
linear |
1 |
6 |
2 |
0 |
4 |
quadratic |
2 |
21 |
5 |
3 |
11 |
cubic |
3 |
56 |
8 |
0 |
24 |
quartic |
4 |
126 |
14 |
6 |
46 |
quintic |
5 |
252 |
20 |
0 |
80 |
sextic |
6 |
462 |
30 |
10 |
130 |
Decomposition into Irreducible representations
Number of nonvanshing force constants
Force field |
Tensor Order |
Ag |
Bg |
Au |
Bu |
linear |
1 |
3 |
0 |
1 |
2 |
quadratic |
2 |
10 |
2 |
3 |
6 |
cubic |
3 |
22 |
6 |
10 |
18 |
quartic |
4 |
48 |
18 |
22 |
38 |
quintic |
5 |
88 |
38 |
48 |
78 |
sextic |
6 |
158 |
78 |
88 |
138 |
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