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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-pVTZ
Scale factor How many Source
Molecules Vibrations
0.941 ± 0.119 27 60 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CH4 Methane 1 A1 3052 2917 0.956 1 1
    2 E 1581 1534 0.971 1 2
    3 T2 3169 3019 0.953 1 3
    4 T2 1356 1306 0.963 1 4
H2 Hydrogen diatomic 1 Σg 4411 4401 0.998 2 5
CS carbon monosulfide 1 Σ 1325 1285 0.970 3 6
HO2 Hydroperoxy radical 1 A' 3724 3436 0.923 4 7
    2 A' 1467 1392 0.949 4 8
    3 A' 1171 1098 0.938 4 9
CH Methylidyne 1 Σ 2853 2861 1.003 5 10
OH Hydroxyl radical 1 Σ 3773 3738 0.991 6 11
HCl Hydrogen chloride 1 Σ 3020 2991 0.990 7 12
HF Hydrogen fluoride 1 Σ 4216 4138 0.982 8 13
NH3 Ammonia 1 A1 3502 3337 0.953 9 14
    2 A1 1109 950 0.856 9 15
    3 E 3626 3444 0.950 9 16
    4 E 1700 1627 0.957 9 17
H2O Water 1 A1 3875 3657 0.944 10 18
    2 A1 1678 1595 0.950 10 19
    3 B2 3979 3756 0.944 10 20
H2S Hydrogen sulfide 1 A1 2737 2615 0.956 11 21
    2 A1 1219 1183 0.970 11 22
    3 B2 2751 2626 0.954 11 23
AlH3 aluminum trihydride 1 A1' 1946 1900 0.976 12 24
    2 A2" 721 698 0.968 12 25
    3 E' 1951 1883 0.965 12 26
    4 E' 796 783 0.985 12 27
PH3 Phosphine 1 A1 2429 2323 0.956 13 28
    2 A1 1030 992 0.963 13 29
    3 E 2436 2328 0.956 13 30
    4 E 1154 1118 0.969 13 31
SiH4 Silane 1 A1 2260 2187 0.968 14 32
    2 E 989 975 0.985 14 33
    3 T2 2266 2191 0.967 14 34
    4 T2 939 914 0.973 14 35
BH3 boron trihydride 2 A2" 1165 1148 0.985 15 36
    3 E' 2705 2602 0.962 15 37
    4 E' 1229 1197 0.974 15 38
PH2 Phosphino radical 1 A1 2403 2310 0.961 16 39
    2 A1 1137 1102 0.969 16 40
SiH3 Silyl radical 1 A1 2228 2136 0.959 17 41
    2 A1 785 728 0.927 17 42
    3 E 2261 2185 0.966 17 43
    4 E 947 922 0.973 17 44
BH Boron monohydride 1 Σ 2361 2367 1.002 18 45
NH2 Amino radical 1 A1 3396 3219 0.948 19 46
    2 A1 1567 1497 0.955 19 47
    3 B2 3487 3301 0.947 19 48
NH Imidogen 1 Σ 3295 3283 0.996 20 49
SiH Silylidyne 1 Σ 2044 2043 0.999 21 50
SiH2 silicon dihydride 1 A1 2075 1996 0.962 22 51
    2 A1 1034 999 0.966 22 52
    3 B2 2072 1993 0.962 22 53
SH Mercapto radical 1 Σ 2707 2696 0.996 23 54
PH phosphorus monohydride 1 Σ 2371 2364 0.997 24 55
AlH aluminum monohydride 1 Σ 1688 1682 0.997 25 56
BH2 boron dihydride 2 A1 1023 954 0.932 26 57
AlH2 aluminum dihydride 1 A1 1856 1770 0.954 27 58
    2 A1 770 760 0.987 27 59
    3 B2 1890 1807 0.956 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