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