## III.B.3.b. (XIII.C.2.) |

# Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at
**MP2/6-311+G(3df,2pd)
**

Scale factor | How many | Source | |
---|---|---|---|

Molecules | Vibrations | ||

0.950 ± | from mp2/cc-pVDZ |

Formula | Name | Mode | Symmetry | Frequency | Count | |||
---|---|---|---|---|---|---|---|---|

Theory | Experiment | ratio | molecules | vibrations |

How do we calculate the scaling factor?

### Histogram of vibrational frequency ratios

#### Ratios greater than 1.35 are in the 1.35 bin. Ratios less than 0.7 are in the 0.7 bin.

20 | |||||||||||||||||||||||||||||||||||||||||||

15 | |||||||||||||||||||||||||||||||||||||||||||

10 | |||||||||||||||||||||||||||||||||||||||||||

5 | |||||||||||||||||||||||||||||||||||||||||||

0 | |||||||||||||||||||||||||||||||||||||||||||

0.70 | 0.75 | 0.80 | 0.85 | 0.90 | 0.95 | 1.00 | 1.05 | 1.10 | 1.15 | 1.20 | 1.25 | 1.30 | 1.35 | ||||||||||||||||||||||||||||||

Ratio of experimental frequency to calculated frequency |