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

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
CH4 Methane 1 A1 3040 2917 0.959 1 1
    2 E 1550 1534 0.990 1 2
    3 T2 3175 3019 0.951 1 3
    4 T2 1333 1306 0.980 1 4
H2 Hydrogen diatomic 1 Σg 4382 4401 1.004 2 5
CS carbon monosulfide 1 Σ 1243 1285 1.034 3 6
HO2 Hydroperoxy radical 1 A' 3644 3436 0.943 4 7
    2 A' 1423 1392 0.978 4 8
    3 A' 1085 1098 1.011 4 9
CH Methylidyne 1 Σ 2811 2861 1.018 5 10
    1 Σ 3128 3145 1.005 5 11
OH Hydroxyl radical 1 Σ 3700 3738 1.010 6 12
HCl Hydrogen chloride 1 Σ 3015 2991 0.992 7 13
HF Hydrogen fluoride 1 Σ 4152 4138 0.997 8 14
NH3 Ammonia 1 A1 3433 3337 0.972 9 15
    2 A1 1181 950 0.805 9 16
    3 E 3561 3444 0.967 9 17
    4 E 1686 1627 0.965 9 18
H2O Water 1 A1 3821 3657 0.957 10 19
    2 A1 1690 1595 0.944 10 20
    3 B2 3927 3756 0.957 10 21
H2S Hydrogen sulfide 1 A1 2727 2615 0.959 11 22
    2 A1 1206 1183 0.981 11 23
    3 B2 2749 2626 0.955 11 24
AlH3 aluminum trihydride 1 A1' 1917 1900 0.991 12 25
    2 A2" 722 698 0.967 12 26
    3 E' 1928 1883 0.976 12 27
    4 E' 791 783 0.990 12 28
PH3 Phosphine 1 A1 2411 2323 0.963 13 29
    2 A1 1034 992 0.960 13 30
    3 E 2423 2328 0.961 13 31
    4 E 1142 1118 0.979 13 32
SiH4 Silane 1 A1 2242 2187 0.975 14 33
    2 E 978 975 0.997 14 34
    3 T2 2253 2191 0.972 14 35
    4 T2 925 914 0.988 14 36
BH3 boron trihydride 2 A2" 1157 1148 0.992 15 37
    3 E' 2698 2602 0.964 15 38
    4 E' 1212 1197 0.987 15 39
PH2 Phosphino radical 1 A1 2381 2310 0.970 16 40
    2 A1 1129 1102 0.976 16 41
SiH3 Silyl radical 1 A1 2209 2136 0.967 17 42
    2 A1 775 728 0.939 17 43
    3 E 2245 2185 0.973 17 44
    4 E 934 922 0.987 17 45
BH Boron monohydride 1 Σ 2341 2367 1.011 18 46
NH2 Amino radical 1 A1 3317 3219 0.971 19 47
    2 A1 1564 1497 0.958 19 48
    3 B2 3414 3301 0.967 19 49
NH Imidogen 1 Σ 3195 3283 1.027 20 50
    1 Σ 3263 3314 1.016 20 51
SiH Silylidyne 1 Σ 2019 2043 1.011 21 52
SiH2 silicon dihydride 1 A1 2055 1996 0.971 22 53
    2 A1 1028 999 0.972 22 54
    3 B2 2053 1993 0.971 22 55
SH Mercapto radical 1 Σ 2693 2696 1.001 23 56
PH phosphorus monohydride 1 Σ 2339 2364 1.011 24 57
    1 Σ 2362 2415 1.023 24 58
AlH aluminum monohydride 1 Σ 1664 1682 1.011 25 59
BH2 boron dihydride 2 A1 1030 954 0.926 26 60
AlH2 aluminum dihydride 1 A1 1822 1770 0.971 27 61
    2 A1 766 760 0.992 27 62
    3 B2 1860 1807 0.971 27 63

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.

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