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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD/6-31+G**
Scale factor How many Source
Molecules Vibrations
0.934 ± 0.113 32 67 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4504 4401 0.977 1 1
LiH Lithium Hydride 1 Σ 1375 1405 1.022 2 2
NaH sodium hydride 1 Σ 1138 1172 1.030 3 3
BeH beryllium monohydride 1 Σ 2098 2061 0.983 4 4
MgH magnesium monohydride 1 Σ 1473 1493 1.013 5 5
BH Boron monohydride 1 Σ 2415 2367 0.980 6 6
AlH aluminum monohydride 1 Σ 1719 1682 0.979 7 7
CH Methylidyne 1 Σ 2889 2861 0.990 8 8
SiH Silylidyne 1 Σ 2081 2043 0.981 9 9
NH Imidogen 1 Σ 3311 3283 0.992 10 10
PH phosphorus monohydride 1 Σ 2398 2364 0.986 11 11
OH Hydroxyl radical 1 Σ 3769 3738 0.992 12 12
HS Mercapto radical 1 Σ 2744 2696 0.983 13 13
CS carbon monosulfide 1 Σ 1335 1285 0.963 14 14
HF Hydrogen fluoride 1 Σ 4151 4138 0.997 15 15
HCl Hydrogen chloride 1 Σ 3064 2991 0.976 16 16
BeH2 beryllium dihydride 2 Σu 2293 2159 0.942 17 17
    3 Πu 717 698 0.973 17 18
MgH2 magnesium dihydride 2 Σu 1619 1572 0.971 18 19
    3 Πu 447 440 0.984 18 20
AlH2 aluminum dihydride 1 A1 1882 1770 0.940 19 21
    2 A1 790 760 0.962 19 22
    3 B2 1921 1807 0.940 19 23
SiH2 silicon dihydride 1 A1 2116 1996 0.943 20 24
    2 A1 1054 999 0.948 20 25
    3 B2 2118 1993 0.941 20 26
NH2 Amino radical 1 A1 3420 3219 0.941 21 27
    2 A1 1559 1497 0.961 21 28
    3 B2 3530 3301 0.935 21 29
PH2 Phosphino radical 1 A1 2439 2310 0.947 22 30
    2 A1 1169 1102 0.943 22 31
H2O Water 1 A1 3380 3657 1.082 23 32
    2 A1 1722 1595 0.926 23 33
    3 B2 3507 3756 1.071 23 34
HO2 Hydroperoxy radical 1 A' 3713 3436 0.925 24 35
    2 A' 1447 1392 0.962 24 36
    3 A' 1130 1098 0.971 24 37
H2S Hydrogen sulfide 1 A1 2782 2615 0.940 25 38
    2 A1 1265 1183 0.935 25 39
    3 B2 2804 2626 0.936 25 40
BH3 boron trihydride 2 A2" 1192 1148 0.963 26 41
    3 E' 2769 2602 0.940 26 42
    4 E' 1253 1197 0.955 26 43
AlH3 aluminum trihydride 1 A1' 1972 1900 0.963 27 44
    2 A2" 726 698 0.961 27 45
    3 E' 1985 1883 0.949 27 46
    4 E' 814 783 0.962 27 47
SiH3 Silyl radical 1 A1 2278 2136 0.938 28 48
    2 A1 804 728 0.905 28 49
    3 E 2313 2185 0.945 28 50
    4 E 969 922 0.952 28 51
NH3 Ammonia 1 A1 3549 3337 0.940 29 52
    2 A1 1072 950 0.886 29 53
    3 E 3700 3444 0.931 29 54
    4 E 1713 1627 0.950 29 55
PH3 Phosphine 1 A1 2470 2323 0.941 30 56
    2 A1 1068 992 0.929 30 57
    3 E 2483 2328 0.938 30 58
    4 E 1163 1118 0.961 30 59
CH4 Methane 1 A1 3097 2917 0.942 31 60
    2 E 1593 1534 0.963 31 61
    3 T2 3225 3019 0.936 31 62
    4 T2 1396 1306 0.936 31 63
SiH4 Silane 1 A1 2308 2187 0.948 32 64
    2 E 1002 975 0.973 32 65
    3 T2 2317 2191 0.946 32 66
    4 T2 961 914 0.951 32 67

How do we calculate the scaling factor? 2015 08 03 12:34

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