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