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

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