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