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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CID/cc-pVTZ
Scale factor How many Source
Molecules Vibrations
0.927 ± 0.122 27 60 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4423 4161 0.941 1 1
BH Boron monohydride 1 Σ 2381 2269 0.953 2 2
AlH aluminum monohydride 1 Σ 1699 1625 0.957 3 3
CH Methylidyne 1 Σ 2891 2733 0.945 4 4
SiH Silylidyne 1 Σ 2063 1971 0.955 5 5
NH Imidogen 1 Σ 3354 3126 0.932 6 6
PH phosphorus monohydride 1 Σ 2394 2276 0.951 7 7
OH Hydroxyl radical 1 Σ 3841 3570 0.929 8 8
HS Mercapto radical 1 Σ 2742 2599 0.948 9 9
CS carbon monosulfide 1 Σ 1379 1272 0.923 10 10
HF Hydrogen fluoride 1 Σ 4279 3961 0.926 11 11
HCl Hydrogen chloride 1 Σ 3060 2886 0.943 12 12
BH2 boron dihydride 2 A1 1031 954 0.925 13 13
AlH2 aluminum dihydride 1 A1 1874 1770 0.944 14 14
    2 A1 777 760 0.978 14 15
    3 B2 1906 1807 0.948 14 16
SiH2 silicon dihydride 1 A1 2102 1996 0.950 15 17
    2 A1 1047 999 0.954 15 18
    3 B2 2099 1993 0.950 15 19
PH2 Phosphino radical 1 A1 2436 2310 0.948 16 20
    2 A1 1152 1102 0.957 16 21
H2O Water 1 A1 3945 3657 0.927 17 22
    2 A1 1691 1595 0.943 17 23
    3 B2 4046 3756 0.928 17 24
HO2 Hydroperoxy radical 1 A' 3856 3436 0.891 18 25
    2 A' 1520 1392 0.916 18 26
    3 A' 1238 1098 0.887 18 27
H2S Hydrogen sulfide 1 A1 2777 2615 0.942 19 28
    2 A1 1237 1183 0.957 19 29
    3 B2 2790 2626 0.941 19 30
BH3 boron trihydride 2 A2" 1173 1148 0.978 20 31
    3 E' 2725 2602 0.955 20 32
    4 E' 1238 1197 0.967 20 33
AlH3 aluminum trihydride 1 A1' 1964 1900 0.967 21 34
    2 A2" 728 698 0.958 21 35
    3 E' 1968 1883 0.957 21 36
    4 E' 803 783 0.976 21 37
SiH3 Silyl radical 1 A1 2250 2136 0.949 22 38
    2 A1 800 728 0.909 22 39
    3 E 2283 2185 0.957 22 40
    4 E 959 922 0.961 22 41
NH3 Ammonia 1 A1 3560 3337 0.937 23 42
    2 A1 1108 950 0.857 23 43
    3 E 3685 3444 0.935 23 44
    4 E 1717 1627 0.948 23 45
PH3 Phosphine 1 A1 2469 2323 0.941 24 46
    2 A1 1042 992 0.952 24 47
    3 E 2476 2328 0.940 24 48
    4 E 1172 1118 0.954 24 49
CH4 Methane 1 A1 3086 2917 0.945 25 50
    2 E 1598 1534 0.960 25 51
    3 T2 3206 3019 0.942 25 52
    4 T2 1372 1306 0.952 25 53
SiH4 Silane 1 A1 2285 2187 0.957 26 54
    2 E 1002 975 0.973 26 55
    3 T2 2290 2191 0.957 26 56
    4 T2 954 914 0.958 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