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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD(T)/cc-pVDZ
Scale factor How many Source
Molecules Vibrations
0.979 ± 0.025 26 57 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4382 4161 0.950 1 1
BH Boron monohydride 1 Σ 2342 2269 0.969 2 2
AlH aluminum monohydride 1 Σ 1665 1625 0.976 3 3
CH Methylidyne 1 Σ 2812 2733 0.972 4 4
    1 Σ 3129     4 5
SiH Silylidyne 1 Σ 2021 1971 0.975 5 6
NH Imidogen 1 Σ 3196 3126 0.978 6 7
PH phosphorus monohydride 1 Σ 2338 2276 0.974 7 8
    1 Σ 2362 2319 0.982 7 9
OH Hydroxyl radical 1 Σ 3701 3570 0.964 8 10
HS Mercapto radical 1 Σ 2693 2599 0.965 9 11
CS carbon monosulfide 1 Σ 1261 1272 1.009 10 12
HF Hydrogen fluoride 1 Σ 4154 3961 0.954 11 13
HCl Hydrogen chloride 1 Σ 3015 2886 0.957 12 14
BH2 boron dihydride 2 A1 1030 954 0.926 13 15
AlH2 aluminum dihydride 1 A1 1823 1770 0.971 14 16
    2 A1 766 760 0.992 14 17
    3 B2 1861 1807 0.971 14 18
SiH2 silicon dihydride 1 A1 2056 1996 0.971 15 19
    2 A1 1029 999 0.971 15 20
    3 B2 2054 1993 0.970 15 21
PH2 Phosphino radical 1 A1 2382 2310 0.970 16 22
    2 A1 1129 1102 0.976 16 23
H2O Water 1 A1 3820 3657 0.957 17 24
    2 A1 1690 1595 0.944 17 25
    3 B2 3926 3756 0.957 17 26
H2S Hydrogen sulfide 1 A1 2727 2615 0.959 18 27
    2 A1 1207 1183 0.980 18 28
    3 B2 2749 2626 0.955 18 29
BH3 boron trihydride 2 A2" 1157 1148 0.991 19 30
    3 E' 2699 2602 0.964 19 31
    4 E' 1212 1197 0.987 19 32
AlH3 aluminum trihydride 1 A1' 1918 1900 0.991 20 33
    2 A2" 722 698 0.966 20 34
    3 E' 1928 1883 0.976 20 35
    4 E' 791 783 0.990 20 36
SiH3 Silyl radical 1 A1 2210 2136 0.967 21 37
    2 A1 775 728 0.939 21 38
    3 E 2246 2185 0.973 21 39
    4 E 934 922 0.987 21 40
NH3 Ammonia 1 A1 3435 3337 0.972 22 41
    2 A1 1181 950 0.805 22 42
    3 E 3562 3444 0.967 22 43
    4 E 1686 1627 0.965 22 44
PH3 Phosphine 1 A1 2412 2323 0.963 23 45
    2 A1 1034 992 0.959 23 46
    3 E 2423 2328 0.961 23 47
    4 E 1143 1118 0.978 23 48
CH4 Methane 1 A1 3041 2917 0.959 24 49
    2 E 1550 1534 0.990 24 50
    3 T2 3176 3019 0.951 24 51
    4 T2 1333 1306 0.980 24 52
SiH4 Silane 1 A1 2242 2187 0.975 25 53
    2 E 978 975 0.997 25 54
    3 T2 2254 2191 0.972 25 55
    4 T2 926 914 0.987 25 56

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 35 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 25 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 15 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 5 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