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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(T)/cc-pVDZ
Scale factor How many Source
Molecules Vibrations
0.979 ± 0.025 26 57 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CH4 Methane 1 A1 3041 2917 0.959 1 1
    2 E 1550 1534 0.990 1 2
    3 T2 3176 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 1261 1285 1.019 3 6
CH Methylidyne 1 Σ 2812 2861 1.017 4 7
    1 Σ 3129 3145 1.005 4 8
OH Hydroxyl radical 1 Σ 3701 3738 1.010 5 9
HCl Hydrogen chloride 1 Σ 3015 2991 0.992 6 10
HF Hydrogen fluoride 1 Σ 4154 4138 0.996 7 11
NH3 Ammonia 1 A1 3435 3337 0.972 8 12
    2 A1 1181 950 0.805 8 13
    3 E 3562 3444 0.967 8 14
    4 E 1686 1627 0.965 8 15
H2O Water 1 A1 3822 3657 0.957 9 16
    2 A1 1690 1595 0.944 9 17
    3 B2 3928 3756 0.956 9 18
H2S Hydrogen sulfide 1 A1 2727 2615 0.959 10 19
    2 A1 1207 1183 0.980 10 20
    3 B2 2749 2626 0.955 10 21
AlH3 aluminum trihydride 1 A1' 1918 1900 0.991 11 22
    2 A2" 722 698 0.966 11 23
    3 E' 1928 1883 0.976 11 24
    4 E' 791 783 0.990 11 25
PH3 Phosphine 1 A1 2412 2323 0.963 12 26
    2 A1 1034 992 0.959 12 27
    3 E 2423 2328 0.961 12 28
    4 E 1143 1118 0.978 12 29
SiH4 Silane 1 A1 2242 2187 0.975 13 30
    2 E 978 975 0.997 13 31
    3 T2 2254 2191 0.972 13 32
    4 T2 926 914 0.987 13 33
BH3 boron trihydride 2 A2" 1157 1148 0.991 14 34
    3 E' 2699 2602 0.964 14 35
    4 E' 1212 1197 0.987 14 36
PH2 Phosphino radical 1 A1 2382 2310 0.970 15 37
    2 A1 1129 1102 0.976 15 38
SiH3 Silyl radical 1 A1 2209 2136 0.967 16 39
    2 A1 775 728 0.939 16 40
    3 E 2246 2185 0.973 16 41
    4 E 935 922 0.987 16 42
BH Boron monohydride 1 Σ 2342 2367 1.010 17 43
NH2 Amino radical 1 A1 3318 3219 0.970 18 44
    2 A1 1564 1497 0.957 18 45
    3 B2 3415 3301 0.967 18 46
NH Imidogen 1 Σ 3196 3283 1.027 19 47
    1 Σ 3264 3314 1.015 19 48
SiH Silylidyne 1 Σ 2021 2043 1.011 20 49
SiH2 silicon dihydride 1 A1 2056 1996 0.971 21 50
    2 A1 1029 999 0.971 21 51
    3 B2 2054 1993 0.970 21 52
SH Mercapto radical 1 Σ 2693 2696 1.001 22 53
PH phosphorus monohydride 1 Σ 2339 2364 1.010 23 54
    1 Σ 2362 2415 1.022 23 55
AlH aluminum monohydride 1 Σ 1665 1682 1.010 24 56
BH2 boron dihydride 2 A1 1030 954 0.926 25 57
AlH2 aluminum dihydride 1 A1 1823 1770 0.971 26 58
    2 A1 766 760 0.992 26 59
    3 B2 1861 1807 0.971 26 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.

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