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

How do we calculate the scaling factor? 2015 08 03 12:34

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.

40 35 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 30 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 25 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 20 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 10 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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