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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at QCISD(T)/cc-pVDZ
Scale factor How many Source
Molecules Vibrations
0.953 ± 0.119 27 60 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 2341 2269 0.969 2 2
AlH aluminum monohydride 1 Σ 1664 1625 0.976 3 3
CH Methylidyne 1 Σ 2811 2733 0.972 4 4
    1 Σ 3128     4 5
SiH Silylidyne 1 Σ 2019 1971 0.976 5 6
NH Imidogen 1 Σ 3195 3126 0.978 6 7
PH phosphorus monohydride 1 Σ 2336 2276 0.975 7 8
    1 Σ 2362 2319 0.982 7 9
OH Hydroxyl radical 1 Σ 3700 3570 0.965 8 10
HS Mercapto radical 1 Σ 2693 2599 0.965 9 11
CS carbon monosulfide 1 Σ 1243 1272 1.023 10 12
HF Hydrogen fluoride 1 Σ 4152 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 1822 1770 0.971 14 16
    2 A1 766 760 0.992 14 17
    3 B2 1860 1807 0.971 14 18
SiH2 silicon dihydride 1 A1 2055 1996 0.971 15 19
    2 A1 1028 999 0.972 15 20
    3 B2 2053 1993 0.971 15 21
PH2 Phosphino radical 1 A1 2381 2310 0.970 16 22
    2 A1 1129 1102 0.976 16 23
H2O Water 1 A1 3818 3657 0.958 17 24
    2 A1 1689 1595 0.944 17 25
    3 B2 3925 3756 0.957 17 26
HO2 Hydroperoxy radical 1 A' 3644 3436 0.943 18 27
    2 A' 1423 1392 0.978 18 28
    3 A' 1085 1098 1.011 18 29
H2S Hydrogen sulfide 1 A1 2727 2615 0.959 19 30
    2 A1 1206 1183 0.981 19 31
    3 B2 2749 2626 0.955 19 32
BH3 boron trihydride 2 A2" 1157 1148 0.992 20 33
    3 E' 2698 2602 0.964 20 34
    4 E' 1212 1197 0.987 20 35
AlH3 aluminum trihydride 1 A1' 1917 1900 0.991 21 36
    2 A2" 722 698 0.967 21 37
    3 E' 1928 1883 0.976 21 38
    4 E' 791 783 0.990 21 39
SiH3 Silyl radical 1 A1 2209 2136 0.967 22 40
    2 A1 774 728 0.940 22 41
    3 E 2246 2185 0.973 22 42
    4 E 934 922 0.987 22 43
NH3 Ammonia 1 A1 3433 3337 0.972 23 44
    2 A1 1181 950 0.805 23 45
    3 E 3561 3444 0.967 23 46
    4 E 1686 1627 0.965 23 47
PH3 Phosphine 1 A1 2411 2323 0.963 24 48
    2 A1 1034 992 0.960 24 49
    3 E 2423 2328 0.961 24 50
    4 E 1142 1118 0.979 24 51
CH4 Methane 1 A1 3040 2917 0.959 25 52
    2 E 1550 1534 0.990 25 53
    3 T2 3175 3019 0.951 25 54
    4 T2 1333 1306 0.980 25 55
SiH4 Silane 1 A1 2242 2187 0.975 26 56
    2 E 978 975 0.997 26 57
    3 T2 2253 2191 0.972 26 58
    4 T2 925 914 0.988 26 59

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