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