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