## III.G.7. (XIII.B.3.) (XIII.D.5.) |

# Compare vibrational frequencies for two calculations
for ZnCH_{2} (Zinc methylene)

### A =
HF/6-31G*

B =
MP2/6-31G*

scale factors=0.8985, 0.943
symmetry | frequency (cm^{-1}) |
reduced mass (amu) | IR Intensity (km mol^{-1}) |
||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

mode number | A | B | A | B | diff. | ratio | A | B | diff. | ratio | A | B | diff. | ratio | |||

1 | A_{1} |
A_{1} |
2924 | 3009 | -85.2 | 0.972 | 1.052 | 1.052 | -0.000 | 1.000 | 58.72 | 19.66 | 39.07 | 2.988 | |||

2 | A_{1} |
A_{1} |
1334 | 1356 | -21.7 | 0.984 | 1.106 | 1.115 | -0.009 | 0.992 | 30.53 | 12.44 | 18.09 | 2.455 | |||

3 | A_{1} |
A_{1} |
489 | 555 | -65.9 | 0.881 | 5.647 | 5.414 | 0.233 | 1.043 | 25.20 | 27.17 | -1.97 | 0.927 | |||

4 | B_{1} |
B_{1} |
578 | 641 | -63.6 | 0.901 | 1.268 | 1.273 | -0.004 | 0.997 | 80.38 | 86.72 | -6.34 | 0.927 | |||

5 | B_{2} |
B_{2} |
3000 | 3103 | -103.0 | 0.967 | 1.110 | 1.111 | -0.001 | 0.999 | 24.38 | 8.51 | 15.87 | 2.866 | |||

6 | B_{2} |
B_{2} |
521 | 563 | -42.4 | 0.925 | 1.167 | 1.173 | -0.005 | 0.995 | 2.62 | 2.19 | 0.42 | 1.192 | |||

scaled by | 0.8985 | 0.943 |

See section **III.C.1** List or set vibrational scaling factors
to change the scale factors used here.

See section **III.C.2**
Calculate a vibrational scaling factor for a given set of molecules
to determine the least squares best scaling factor.