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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at MP2=FULL/STO-3G
Scale factor How many Source
Molecules Vibrations
0.889 ± 0.073 19 103 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CO Carbon monoxide 1 Σ 2010 2170 1.080 1 1
H2 Hydrogen diatomic 1 Σg 5245 4401 0.839 2 2
LiH Lithium Hydride 1 Σ 1781 1405 0.789 3 3
HCl Hydrogen chloride 1 Σ 3213 2991 0.931 4 4
HF Hydrogen fluoride 1 Σ 4144 4138 0.999 5 5
SO2 Sulfur dioxide 3 B2 2047 1362 0.665 6 6
    2 A1 443 518 1.169 6 7
    1 A1 1050 1151 1.097 6 8
CH Methylidyne 1 Σ 3577 3145 0.879 7 9
C6H6 Fulvene 30 B2 350 350 1.000 8 10
    29 B2 852 795 0.933 8 11
    28 B2 1035 952 0.920 8 12
    27 B2 1183 1077 0.910 8 13
    26 B2 1347 1232 0.914 8 14
    25 B2 1456 1314 0.902 8 15
    24 B2 1714 1550 0.905 8 16
    23 B2 3525 3075 0.872 8 17
    22 B2 3552 3104 0.874 8 18
    21 B2 3600     8 19
    20 B1 201     8 20
    19 B1 641 613 0.956 8 21
    18 B1 836 769 0.920 8 22
    17 B1 974 907 0.931 8 23
    16 B1 1014 926 0.913 8 24
    15 A2 524 494 0.943 8 25
    14 A2 769 666 0.866 8 26
    13 A2 858     8 27
    12 A2 999     8 28
    11 A1 701 641 0.914 8 29
    10 A1 948 894 0.943 8 30
    9 A1 1062 986 0.929 8 31
    8 A1 1182 1082 0.916 8 32
    7 A1 1486 1342 0.903 8 33
    6 A1 1586 1449 0.913 8 34
    5 A1 1653 1486 0.899 8 35
    4 A1 1792 1632 0.911 8 36
    3 A1 3444 3008 0.873 8 37
    2 A1 3531 3051 0.864 8 38
    1 A1 3560 3088 0.868 8 39
CO2 Carbon dioxide 3 Πu 478 667 1.395 9 40
    2 Σu 2598 2349 0.904 9 41
    1 Σg 1276 1333 1.045 9 42
C3H2N2 Malononitrile 15 B2 353 366 1.036 10 43
    14 B2 997 982 0.985 10 44
    13 B2 1460 1318 0.903 10 45
    12 B2 2110 2275 1.078 10 46
    11 B1 324 337 1.040 10 47
    10 B1 1038 933 0.899 10 48
    9 B1 3497 2968 0.849 10 49
    8 A2 343 367 1.069 10 50
    7 A2 1347 1220 0.906 10 51
    6 A1 141 167 1.182 10 52
    5 A1 577 582 1.009 10 53
    4 A1 918 890 0.969 10 54
    3 A1 1648 1395 0.847 10 55
    2 A1 2103 2275 1.082 10 56
    1 A1 3393 2935 0.865 10 57
C3H6 Cyclopropane 14 E" 826 739 0.895 11 58
    13 E" 1340 1188 0.886 11 59
    12 E" 3613 3082 0.853 11 60
    11 E' 1030 866 0.841 11 61
    10 E' 1269 1029 0.811 11 62
    9 E' 1644 1438 0.875 11 63
    8 E' 3457 3025 0.875 11 64
    7 A2" 902 854 0.946 11 65
    6 A2" 3619 3103 0.857 11 66
    5 A2' 1244 1070 0.860 11 67
    4 A1" 1302 1126 0.865 11 68
    3 A1' 1335 1188 0.890 11 69
    2 A1' 1695 1479 0.872 11 70
    1 A1' 3473 3038 0.875 11 71
C2H2 Acetylene 5 Πu 837 730 0.872 12 72
    4 Πg 715 612 0.856 12 73
    3 Σu 3677 3289 0.894 12 74
    2 Σg 2091 1974 0.944 12 75
    1 Σg 3791 3374 0.890 12 76
C2H4 Ethylene 12 B3u 1039 949 0.913 13 77
    11 B3g 1356 1217 0.898 13 78
    10 B3g 3612 3086 0.854 13 79
    9 B2u 880 826 0.938 13 80
    8 B2u 3625 3105 0.857 13 81
    7 B2g 1000 940 0.939 13 82
    6 B1u 1633 1444 0.884 13 83
    5 B1u 3451 2989 0.866 13 84
    4 Au 1188 1023 0.861 13 85
    3 Ag 1485 1342 0.904 13 86
    2 Ag 1810 1623 0.897 13 87
    1 Ag 3481 3026 0.869 13 88
CH4 Methane 4 T2 1577 1306 0.828 14 89
    3 T2 3602 3019 0.838 14 90
    2 E 1810 1534 0.848 14 91
    1 A1 3344 2917 0.872 14 92
H2CO Formaldehyde 6 B2 1297 1249 0.963 15 93
    5 B2 3400 2843 0.836 15 94
    4 B1 1130 1167 1.033 15 95
    3 A1 1607 1500 0.933 15 96
    2 A1 1800 1746 0.970 15 97
    1 A1 3267 2782 0.852 15 98
NH3 Ammonia 3 E 3814 3444 0.903 16 99
    2 A1 1460 950 0.651 16 100
    1 A1 3539 3337 0.943 16 101
    4 E 1991 1627 0.817 16 102
N2 Nitrogen diatomic 1 Σg 1669 2359 1.413 17 103
H2O Water 1 A1 3798 3657 0.963 18 104
    2 A1 2076 1595 0.768 18 105
    3 B2 4057 3756 0.926 18 106
F2 Fluorine diatomic 1 Σg 1464 917 0.626 19 107

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.

35
30
25
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