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