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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD/cc-pVDZ
Scale factor How many Source
Molecules Vibrations
0.947 ± 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 4383 4161 0.949 1 1
BH Boron monohydride 1 Σ 2351 2269 0.965 2 2
AlH aluminum monohydride 1 Σ 1671 1625 0.972 3 3
CH Methylidyne 1 Σ 2827 2733 0.967 4 4
SiH Silylidyne 1 Σ 2032 1971 0.970 5 5
NH Imidogen 1 Σ 3219 3126 0.971 6 6
PH phosphorus monohydride 1 Σ 2354 2276 0.967 7 7
OH Hydroxyl radical 1 Σ 3726 3570 0.958 8 8
HS Mercapto radical 1 Σ 2709 2599 0.959 9 9
CS carbon monosulfide 1 Σ 1317 1272 0.966 10 10
HF Hydrogen fluoride 1 Σ 4169 3961 0.950 11 11
HCl Hydrogen chloride 1 Σ 3032 2886 0.952 12 12
BH2 boron dihydride 2 A1 1033 954 0.923 13 13
AlH2 aluminum dihydride 1 A1 1830 1770 0.967 14 14
    2 A1 770 760 0.988 14 15
    3 B2 1867 1807 0.968 14 16
SiH2 silicon dihydride 1 A1 2069 1996 0.965 15 17
    2 A1 1036 999 0.964 15 18
    3 B2 2066 1993 0.965 15 19
PH2 Phosphino radical 1 A1 2397 2310 0.964 16 20
    2 A1 1138 1102 0.968 16 21
H2O Water 1 A1 3846 3657 0.951 17 22
    2 A1 1697 1595 0.940 17 23
    3 B2 3950 3756 0.951 17 24
HO2 Hydroperoxy radical 1 A' 3676 3436 0.935 18 25
    2 A' 1453 1392 0.958 18 26
    3 A' 1133 1098 0.969 18 27
H2S Hydrogen sulfide 1 A1 2743 2615 0.953 19 28
    2 A1 1216 1183 0.972 19 29
    3 B2 2763 2626 0.950 19 30
BH3 boron trihydride 2 A2" 1161 1148 0.989 20 31
    3 E' 2705 2602 0.962 20 32
    4 E' 1216 1197 0.984 20 33
AlH3 aluminum trihydride 1 A1' 1924 1900 0.987 21 34
    2 A2" 725 698 0.963 21 35
    3 E' 1934 1883 0.974 21 36
    4 E' 794 783 0.987 21 37
SiH3 Silyl radical 1 A1 2219 2136 0.962 22 38
    2 A1 782 728 0.931 22 39
    3 E 2254 2185 0.970 22 40
    4 E 940 922 0.981 22 41
NH3 Ammonia 1 A1 3461 3337 0.964 23 42
    2 A1 1178 950 0.807 23 43
    3 E 3586 3444 0.960 23 44
    4 E 1694 1627 0.960 23 45
PH3 Phosphine 1 A1 2427 2323 0.957 24 46
    2 A1 1041 992 0.953 24 47
    3 E 2438 2328 0.955 24 48
    4 E 1152 1118 0.971 24 49
CH4 Methane 1 A1 3054 2917 0.955 25 50
    2 E 1558 1534 0.985 25 51
    3 T2 3186 3019 0.947 25 52
    4 T2 1342 1306 0.973 25 53
SiH4 Silane 1 A1 2251 2187 0.972 26 54
    2 E 983 975 0.992 26 55
    3 T2 2260 2191 0.969 26 56
    4 T2 932 914 0.981 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