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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-311G**
Scale factor How many Source
Molecules Vibrations
0.913 ± 0.048 12 37 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
C2H5 Ethyl radical 14 A' 3271 3033 0.927 1 1
    12 A' 3191 2842 0.891 1 2
    8 A' 1587 1440 0.907 1 3
    7 A' 1524 1366 0.896 1 4
    5 A' 1107 1138 1.028 1 5
    2 A' 529 528 0.997 1 6
    15 A" 3369 3112 0.924 1 7
    13 A" 3223 2987 0.927 1 8
    10 A" 1605 1440 0.897 1 9
    6 A" 1299 1175 0.904 1 10
CH2OH Hydroxymethyl radical 1 A 4189 3650 0.871 2 11
    4 A 1609 1459 0.907 2 12
    5 A 1473 1334 0.906 2 13
    6 A 1276 1176 0.922 2 14
    7 A 1154 1048 0.908 2 15
    8 A 901 482 0.535 2 16
    9 A 416 234 0.563 2 17
C2H3 vinyl 1 A' 3378 3141 0.930 3 18
    2 A' 3336 2953 0.885 3 19
    3 A' 3250 2912 0.896 3 20
    5 A' 1505 1360 0.903 3 21
    7 A' 826 674 0.816 3 22
    8 A" 1052 895 0.851 3 23
    9 A" 964 857 0.889 3 24
BN boron nitride 1 Σ 1792 1520 0.848 4 25
NO Nitric oxide 1 Σ 2279 1904 0.836 5 26
PO2 Phosphorus dioxide 1 A1 1250 1076 0.861 6 27
    2 A1 468 397 0.848 6 28
    3 B2 1557 1328 0.853 6 29
BO boron monoxide 1 Σ 2108 1885 0.894 7 30
SeO Selenium monoxide 1 Σ 1074 915 0.852 8 31
BeH beryllium monohydride 1 Σ 2135 2061 0.965 9 32
HSe Selenium monohydride 1 Σ 2563 2400 0.936 10 33
MgF Magnesium monofluoride 1 Σ 743 712 0.958 11 34
AlN Aluminum nitride 1 Σ 730 747 1.023 12 35

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