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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD/cc-pVTZ
Scale factor How many Source
Molecules Vibrations
0.941 ± 0.119 27 60 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4411 4161 0.943 1 1
BH Boron monohydride 1 Σ 2361 2269 0.961 2 2
AlH aluminum monohydride 1 Σ 1688 1625 0.963 3 3
CH Methylidyne 1 Σ 2858 2733 0.956 4 4
SiH Silylidyne 1 Σ 2045 1971 0.964 5 5
NH Imidogen 1 Σ 3295 3126 0.949 6 6
PH phosphorus monohydride 1 Σ 2371 2276 0.960 7 7
OH Hydroxyl radical 1 Σ 3777 3570 0.945 8 8
HS Mercapto radical 1 Σ 2707 2599 0.960 9 9
CS carbon monosulfide 1 Σ 1325 1272 0.960 10 10
HF Hydrogen fluoride 1 Σ 4211 3961 0.941 11 11
HCl Hydrogen chloride 1 Σ 3019 2886 0.956 12 12
BH2 boron dihydride 2 A1 1023 954 0.932 13 13
AlH2 aluminum dihydride 1 A1 1856 1770 0.954 14 14
    2 A1 770 760 0.987 14 15
    3 B2 1890 1807 0.956 14 16
SiH2 silicon dihydride 1 A1 2075 1996 0.962 15 17
    2 A1 1034 999 0.966 15 18
    3 B2 2072 1993 0.962 15 19
PH2 Phosphino radical 1 A1 2403 2310 0.961 16 20
    2 A1 1137 1102 0.969 16 21
H2O Water 1 A1 3876 3657 0.944 17 22
    2 A1 1678 1595 0.950 17 23
    3 B2 3979 3756 0.944 17 24
HO2 Hydroperoxy radical 1 A' 3721 3436 0.923 18 25
    2 A' 1467 1392 0.949 18 26
    3 A' 1170 1098 0.938 18 27
H2S Hydrogen sulfide 1 A1 2737 2615 0.955 19 28
    2 A1 1219 1183 0.970 19 29
    3 B2 2752 2626 0.954 19 30
BH3 boron trihydride 2 A2" 1165 1148 0.985 20 31
    3 E' 2705 2602 0.962 20 32
    4 E' 1229 1197 0.974 20 33
AlH3 aluminum trihydride 1 A1' 1947 1900 0.976 21 34
    2 A2" 721 698 0.968 21 35
    3 E' 1952 1883 0.965 21 36
    4 E' 795 783 0.985 21 37
SiH3 Silyl radical 1 A1 2228 2136 0.959 22 38
    2 A1 785 728 0.927 22 39
    3 E 2261 2185 0.966 22 40
    4 E 947 922 0.973 22 41
NH3 Ammonia 1 A1 3502 3337 0.953 23 42
    2 A1 1109 950 0.856 23 43
    3 E 3626 3444 0.950 23 44
    4 E 1700 1627 0.957 23 45
PH3 Phosphine 1 A1 2430 2323 0.956 24 46
    2 A1 1030 992 0.963 24 47
    3 E 2437 2328 0.955 24 48
    4 E 1154 1118 0.969 24 49
CH4 Methane 1 A1 3050 2917 0.956 25 50
    2 E 1581 1534 0.970 25 51
    3 T2 3167 3019 0.953 25 52
    4 T2 1356 1306 0.963 25 53
SiH4 Silane 1 A1 2260 2187 0.968 26 54
    2 E 989 975 0.986 26 55
    3 T2 2266 2191 0.967 26 56
    4 T2 939 914 0.973 26 57

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 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