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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD(T)/6-31+G**
Scale factor How many Source
Molecules Vibrations
0.960 ± 0.026 33 68 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4505 4161 0.924 1 1
LiH Lithium Hydride 1 Σ 1375 1360 0.989 2 2
NaH sodium hydride 1 Σ 1138 1133 0.996 3 3
BeH beryllium monohydride 1 Σ 2092 1987 0.950 4 4
MgH magnesium monohydride 1 Σ 1469 1432 0.975 5 5
BH Boron monohydride 1 Σ 2411 2269 0.941 6 6
AlH aluminum monohydride 1 Σ 1713 1625 0.949 7 7
CH Methylidyne 1 Σ 2875 2733 0.951 8 8
SiH Silylidyne 1 Σ 2071 1971 0.951 9 9
NH Imidogen 1 Σ 3289 3126 0.950 10 10
PH phosphorus monohydride 1 Σ 2384 2276 0.955 11 11
OH Hydroxyl radical 1 Σ 3747 3570 0.953 12 12
HS Mercapto radical 1 Σ 2728 2599 0.953 13 13
CS carbon monosulfide 1 Σ 1281 1272 0.993 14 14
HF Hydrogen fluoride 1 Σ 4127 3961 0.960 15 15
HCl Hydrogen chloride 1 Σ 3048 2886 0.947 16 16
BeH2 beryllium dihydride 2 Σu 2291 2159 0.943 17 17
    3 Πu 716 698 0.975 17 18
MgH2 magnesium dihydride 2 Σu 1617 1572 0.972 18 19
    3 Πu 446 440 0.986 18 20
BH2 boron dihydride 2 A1 1060 954 0.899 19 21
AlH2 aluminum dihydride 1 A1 1875 1770 0.944 20 22
    2 A1 788 760 0.964 20 23
    3 B2 1915 1807 0.943 20 24
SiH2 silicon dihydride 1 A1 2107 1996 0.947 21 25
    2 A1 1046 999 0.955 21 26
    3 B2 2110 1993 0.944 21 27
PH2 Phosphino radical 1 A1 2425 2310 0.953 22 28
    2 A1 1160 1102 0.950 22 29
H2O Water 1 A1 3855 3657 0.949 23 30
    2 A1 1640 1595 0.973 23 31
    3 B2 3987 3756 0.942 23 32
NaOH sodium hydroxide 1 Σ 3992 3637 0.911 24 33
    2 Σ 549 540 0.984 24 34
    3 Π 320 300 0.937 24 35
H2S Hydrogen sulfide 1 A1 2766 2615 0.945 25 36
    2 A1 1256 1183 0.942 25 37
    3 B2 2790 2626 0.941 25 38
BH3 boron trihydride 2 A2" 1189 1148 0.965 26 39
    3 E' 2763 2602 0.942 26 40
    4 E' 1250 1197 0.958 26 41
AlH3 aluminum trihydride 1 A1' 1966 1900 0.967 27 42
    2 A2" 724 698 0.963 27 43
    3 E' 1979 1883 0.951 27 44
    4 E' 812 783 0.964 27 45
SiH3 Silyl radical 1 A1 2268 2136 0.942 28 46
    2 A1 799 728 0.911 28 47
    3 E 2305 2185 0.948 28 48
    4 E 964 922 0.956 28 49
NH3 Ammonia 1 A1 3525 3337 0.947 29 50
    2 A1 1075 950 0.884 29 51
    3 E 3679 3444 0.936 29 52
    4 E 1705 1627 0.954 29 53
PH3 Phosphine 1 A1 2459 2323 0.945 30 54
    2 A1 1061 992 0.935 30 55
    3 E 2473 2328 0.941 30 56
    4 E 1153 1118 0.969 30 57
CH4 Methane 1 A1 3083 2917 0.946 31 58
    2 E 1585 1534 0.968 31 59
    3 T2 3212 3019 0.940 31 60
    4 T2 1389 1306 0.941 31 61
SiH4 Silane 1 A1 2299 2187 0.951 32 62
    2 E 997 975 0.978 32 63
    3 T2 2309 2191 0.949 32 64
    4 T2 956 914 0.956 32 65

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 60 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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