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