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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at CCSD/cc-pVDZ
Scale factor How many Source
Molecules Vibrations
0.947 ± 0.119 27 60 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CH4 Methane 1 A1 3055 2917 0.955 1 1
    2 E 1557 1534 0.985 1 2
    3 T2 3188 3019 0.947 1 3
    4 T2 1342 1306 0.973 1 4
H2 Hydrogen diatomic 1 Σg 4383 4401 1.004 2 5
CS carbon monosulfide 1 Σ 1317 1285 0.975 3 6
HO2 Hydroperoxy radical 1 A' 3679 3436 0.934 4 7
    2 A' 1452 1392 0.958 4 8
    3 A' 1133 1098 0.969 4 9
CH Methylidyne 1 Σ 2827 2861 1.012 5 10
OH Hydroxyl radical 1 Σ 3726 3738 1.003 6 11
HCl Hydrogen chloride 1 Σ 3028 2991 0.988 7 12
HF Hydrogen fluoride 1 Σ 4173 4138 0.992 8 13
NH3 Ammonia 1 A1 3461 3337 0.964 9 14
    2 A1 1178 950 0.807 9 15
    3 E 3586 3444 0.960 9 16
    4 E 1694 1627 0.960 9 17
H2O Water 1 A1 3846 3657 0.951 10 18
    2 A1 1696 1595 0.940 10 19
    3 B2 3951 3756 0.951 10 20
H2S Hydrogen sulfide 1 A1 2743 2615 0.953 11 21
    2 A1 1216 1183 0.972 11 22
    3 B2 2763 2626 0.950 11 23
AlH3 aluminum trihydride 1 A1' 1923 1900 0.988 12 24
    2 A2" 725 698 0.962 12 25
    3 E' 1933 1883 0.974 12 26
    4 E' 794 783 0.987 12 27
PH3 Phosphine 1 A1 2427 2323 0.957 13 28
    2 A1 1041 992 0.953 13 29
    3 E 2438 2328 0.955 13 30
    4 E 1152 1118 0.971 13 31
SiH4 Silane 1 A1 2251 2187 0.972 14 32
    2 E 983 975 0.992 14 33
    3 T2 2260 2191 0.969 14 34
    4 T2 932 914 0.981 14 35
BH3 boron trihydride 2 A2" 1161 1148 0.989 15 36
    3 E' 2705 2602 0.962 15 37
    4 E' 1216 1197 0.984 15 38
PH2 Phosphino radical 1 A1 2397 2310 0.964 16 39
    2 A1 1138 1102 0.968 16 40
SiH3 Silyl radical 1 A1 2219 2136 0.963 17 41
    2 A1 782 728 0.931 17 42
    3 E 2253 2185 0.970 17 43
    4 E 940 922 0.981 17 44
BH Boron monohydride 1 Σ 2351 2367 1.007 18 45
NH2 Amino radical 1 A1 3344 3219 0.963 19 46
    2 A1 1571 1497 0.953 19 47
    3 B2 3438 3301 0.960 19 48
NH Imidogen 1 Σ 3219 3283 1.020 20 49
SiH Silylidyne 1 Σ 2032 2043 1.005 21 50
SiH2 silicon dihydride 1 A1 2069 1996 0.965 22 51
    2 A1 1036 999 0.964 22 52
    3 B2 2066 1993 0.965 22 53
SH Mercapto radical 1 Σ 2709 2696 0.995 23 54
PH phosphorus monohydride 1 Σ 2356 2364 1.003 24 55
AlH aluminum monohydride 1 Σ 1671 1682 1.007 25 56
BH2 boron dihydride 2 A1 1033 954 0.923 26 57
AlH2 aluminum dihydride 1 A1 1830 1770 0.967 27 58
    2 A1 770 760 0.988 27 59
    3 B2 1867 1807 0.968 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.

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