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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCD/cc-pVTZ
Scale factor How many Source
Molecules Vibrations
0.934 ± 0.170 31 100 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4422 4161 0.941 1 1
BH Boron monohydride 1 Σ 2369 2269 0.958 2 2
AlH aluminum monohydride 1 Σ 1695 1625 0.959 3 3
CH Methylidyne 1 Σ 2873 2733 0.951 4 4
    1 Σ 3151     4 5
SiH Silylidyne 1 Σ 2054 1971 0.960 5 6
NH Imidogen 1 Σ 3332 3126 0.938 6 7
PH phosphorus monohydride 1 Σ 2378 2276 0.957 7 8
    1 Σ 2401 2319 0.966 7 9
OH Hydroxyl radical 1 Σ 3802 3570 0.939 8 10
HS Mercapto radical 1 Σ 2716 2599 0.957 9 11
CS carbon monosulfide 1 Σ 1354 1272 0.940 10 12
HF Hydrogen fluoride 1 Σ 4230 3961 0.937 11 13
HCl Hydrogen chloride 1 Σ 3031 2886 0.952 12 14
BH2 boron dihydride 2 A1 1026 954 0.929 13 15
AlH2 aluminum dihydride 1 A1 1865 1770 0.949 14 16
    2 A1 773 760 0.983 14 17
    3 B2 1898 1807 0.952 14 18
SiH2 silicon dihydride 1 A1 2086 1996 0.957 15 19
    2 A1 1038 999 0.963 15 20
    3 B2 2084 1993 0.956 15 21
PH2 Phosphino radical 1 A1 2412 2310 0.958 16 22
    2 A1 1141 1102 0.966 16 23
H2O Water 1 A1 3892 3657 0.940 17 24
    2 A1 1680 1595 0.949 17 25
    3 B2 3996 3756 0.940 17 26
H2S Hydrogen sulfide 1 A1 2743 2615 0.953 18 27
    2 A1 1221 1183 0.969 18 28
    3 B2 2758 2626 0.952 18 29
CF2 Difluoromethylene 1 A1 1301 1225 0.942 19 30
    2 A1 693 667 0.962 19 31
    3 B2 1207 1114 0.923 19 32
BH3 boron trihydride 2 A2" 1167 1148 0.983 20 33
    3 E' 2711 2602 0.960 20 34
    4 E' 1231 1197 0.972 20 35
AlH3 aluminum trihydride 1 A1' 1952 1900 0.973 21 36
    2 A2" 723 698 0.965 21 37
    3 E' 1957 1883 0.962 21 38
    4 E' 798 783 0.982 21 39
SiH3 Silyl radical 1 A1 2234 2136 0.956 22 40
    2 A1 789 728 0.923 22 41
    3 E 2268 2185 0.964 22 42
    4 E 951 922 0.969 22 43
NH3 Ammonia 1 A1 3513 3337 0.950 23 44
    2 A1 1107 950 0.858 23 45
    3 E 3640 3444 0.946 23 46
    4 E 1702 1627 0.956 23 47
PH3 Phosphine 1 A1 2438 2323 0.953 24 48
    2 A1 1031 992 0.963 24 49
    3 E 2447 2328 0.951 24 50
    4 E 1158 1118 0.966 24 51
HNCO Isocyanic acid 1 A' 3736 3538 0.947 25 52
    2 A' 2367 2269 0.958 25 53
    3 A' 1358 1327 0.977 25 54
    4 A' 825 777 0.942 25 55
    5 A' 570 577 1.013 25 56
    6 A" 652 656 1.006 25 57
CH4 Methane 1 A1 3055 2917 0.955 26 58
    2 E 1583 1534 0.969 26 59
    3 T2 3177 3019 0.950 26 60
    4 T2 1358 1306 0.962 26 61
SiH4 Silane 1 A1 2264 2187 0.966 27 62
    2 E 992 975 0.983 27 63
    3 T2 2271 2191 0.965 27 64
    4 T2 943 914 0.969 27 65
CCl4 Carbon tetrachloride 1 A1 474 459 0.969 28 66
    2 E 223 217 0.972 28 67
    3 T2 834 776 0.930 28 68
    4 T2 323 314 0.973 28 69
C3H4 cyclopropene 1 A1 3345 3158 0.944 29 70
    2 A1 3098 2909 0.939 29 71
    3 A1 1737 1653 0.952 29 72
    4 A1 1547 1483 0.959 29 73
    5 A1 1184 1110 0.938 29 74
    6 A1 944 905 0.958 29 75
    7 A2 1036 996 0.961 29 76
    8 A2 867 820 0.946 29 77
    9 B1 3170 2995 0.945 29 78
    10 B1 1127 1088 0.965 29 79
    11 B1 605 569 0.940 29 80
    12 B2 3296 3124 0.948 29 81
    13 B2 1099 1043 0.949 29 82
    14 B2 1066 1011 0.948 29 83
    15 B2 817 769 0.941 29 84
CH3NH2 methyl amine 1 A' 3546 3361 0.948 30 85
    2 A' 3107 2961 0.953 30 86
    3 A' 3025 2820 0.932 30 87
    4 A' 1688 1623 0.962 30 88
    5 A' 1524 1473 0.966 30 89
    6 A' 1478 1430 0.968 30 90
    7 A' 1200 1130 0.942 30 91
    8 A' 1087 1044 0.960 30 92
    9 A' 883 780 0.884 30 93
    10 A" 3627 3427 0.945 30 94
    11 A" 3142 2985 0.950 30 95
    12 A" 1543 1485 0.962 30 96
    13 A" 1373 1335 0.972 30 97
    14 A" 987     30 98
    15 A" 307 268 0.872 30 99

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.

40 90 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 80 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 70 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 60 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 50 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 30 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 20 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 10 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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