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III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at CID/cc-pVTZ
Scale factor How many Source
Molecules Vibrations
0.927 ± 0.122 27 60 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CH4 Methane 1 A1 3086 2917 0.945 1 1
    2 E 1598 1534 0.960 1 2
    3 T2 3206 3019 0.942 1 3
    4 T2 1372 1306 0.952 1 4
H2 Hydrogen diatomic 1 Σg 4423 4401 0.995 2 5
CS carbon monosulfide 1 Σ 1379 1285 0.932 3 6
HO2 Hydroperoxy radical 1 A' 3856 3436 0.891 4 7
    2 A' 1520 1392 0.916 4 8
    3 A' 1238 1098 0.887 4 9
CH Methylidyne 1 Σ 2891 2861 0.990 5 10
OH Hydroxyl radical 1 Σ 3841 3738 0.973 6 11
HCl Hydrogen chloride 1 Σ 3060 2991 0.978 7 12
HF Hydrogen fluoride 1 Σ 4279 4138 0.967 8 13
NH3 Ammonia 1 A1 3560 3337 0.937 9 14
    2 A1 1108 950 0.857 9 15
    3 E 3685 3444 0.935 9 16
    4 E 1717 1627 0.948 9 17
H2O Water 1 A1 3947 3657 0.926 10 18
    2 A1 1691 1595 0.943 10 19
    3 B2 4048 3756 0.928 10 20
H2S Hydrogen sulfide 1 A1 2777 2615 0.942 11 21
    2 A1 1237 1183 0.957 11 22
    3 B2 2790 2626 0.941 11 23
AlH3 aluminum trihydride 1 A1' 1964 1900 0.967 12 24
    2 A2" 728 698 0.958 12 25
    3 E' 1968 1883 0.957 12 26
    4 E' 803 783 0.976 12 27
PH3 Phosphine 1 A1 2469 2323 0.941 13 28
    2 A1 1042 992 0.952 13 29
    3 E 2476 2328 0.940 13 30
    4 E 1172 1118 0.954 13 31
SiH4 Silane 1 A1 2285 2187 0.957 14 32
    2 E 1002 975 0.973 14 33
    3 T2 2290 2191 0.957 14 34
    4 T2 954 914 0.958 14 35
BH3 boron trihydride 2 A2" 1173 1148 0.978 15 36
    3 E' 2725 2602 0.955 15 37
    4 E' 1238 1197 0.967 15 38
PH2 Phosphino radical 1 A1 2436 2310 0.948 16 39
    2 A1 1152 1102 0.957 16 40
SiH3 Silyl radical 1 A1 2250 2136 0.949 17 41
    2 A1 800 728 0.910 17 42
    3 E 2283 2185 0.957 17 43
    4 E 959 922 0.961 17 44
BH Boron monohydride 1 Σ 2381 2367 0.994 18 45
NH2 Amino radical 1 A1 3453 3219 0.932 19 46
    2 A1 1580 1497 0.948 19 47
    3 B2 3544 3301 0.932 19 48
NH Imidogen 1 Σ 3354 3283 0.979 20 49
SiH Silylidyne 1 Σ 2065 2043 0.989 21 50
SiH2 silicon dihydride 1 A1 2102 1996 0.950 22 51
    2 A1 1047 999 0.954 22 52
    3 B2 2099 1993 0.950 22 53
SH Mercapto radical 1 Σ 2742 2696 0.983 23 54
PH phosphorus monohydride 1 Σ 2394 2364 0.987 24 55
AlH aluminum monohydride 1 Σ 1699 1682 0.990 25 56
BH2 boron dihydride 2 A1 1031 954 0.925 26 57
AlH2 aluminum dihydride 1 A1 1874 1770 0.944 27 58
    2 A1 777 760 0.978 27 59
    3 B2 1906 1807 0.948 27 60

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.

45
40
35
30
25
20
15
10
5
0
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