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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-31G**
Scale factor How many Source
Molecules Vibrations
0.855 ± 0.155 37 60 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
CF3 Trifluoromethyl radical 1 A1 1220 1089 0.892 1 1
    2 A1 759 701 0.924 1 2
    3 E 1442 1260 0.874 1 3
    4 E 550 509 0.924 1 4
HCO Formyl radical 1 A' 2976 2434 0.818 2 5
    2 A' 2154 1868 0.867 2 6
    3 A' 1264 1081 0.855 2 7
C3H3 Propargyl radical 1 A1 3644 3322 0.912 3 8
    6 B1 761 687 0.903 3 9
    7 B1 495 490 0.990 3 10
HO2 Hydroperoxy radical 1 A' 4085 3436 0.841 4 11
    2 A' 1603 1392 0.868 4 12
    3 A' 1252 1098 0.877 4 13
CH Methylidyne 1 Σ 3029 2861 0.944 5 14
OH Hydroxyl radical 1 Σ 4069 3738 0.918 6 15
NF2 Difluoroamino radical 1 A1 1270 1075 0.846 7 16
    2 A1 653 573 0.877 7 17
    3 B2 1193 942 0.790 7 18
CF Fluoromethylidyne 1 Σ 1410 1308 0.927 8 19
CCl carbon monochloride 1 Σ 872 877 1.006 9 20
OClO Chlorine dioxide 1 A1 1070 946 0.883 10 21
    2 A1 508 448 0.882 10 22
    3 B2 1275 1110 0.870 10 23
SiF silicon monofluoride 1 Σ 919 857 0.932 11 24
SiN Silicon nitride 1 Σ 1319 1151 0.873 12 25
LiO lithium oxide 1 Σ 888 815 0.917 13 26
BS boron sulfide 1 Σ 1269 1180 0.930 14 27
AlS Aluminum sulfide 1 Σ 681 617 0.906 15 28
CP Carbon monophosphide 1 Σ 1453 1240 0.853 16 29
NaO sodium monoxide 1 Σ 525 492 0.938 17 30
BeF Beryllium monofluoride 1 Σ 1318 1247 0.947 18 31
PH2 Phosphino radical 1 A1 2554 2310 0.905 19 32
    2 A1 1243 1102 0.886 19 33
SiH3 Silyl radical 1 A1 2340 2136 0.913 20 34
    2 A1 896 728 0.813 20 35
    3 E 2359 2185 0.926 20 36
    4 E 1018 922 0.905 20 37
NH2 Amino radical 1 A1 3627 3219 0.888 21 38
    2 A1 1669 1497 0.897 21 39
    3 B2 3725 3301 0.886 21 40
NH Imidogen 1 Σ 3551 3283 0.924 22 41
SiH Silylidyne 1 Σ 2164 2043 0.944 23 42
BeCl beryllium chloride 1 Σ 856 847 0.990 24 43
SH Mercapto radical 1 Σ 2878 2696 0.937 25 44
SiCl Clorosilylidyne 1 Σ 532 536 1.008 26 45
PH phosphorus monohydride 1 Σ 2526 2364 0.936 27 46
MgH magnesium monohydride 1 Σ 1577 1493 0.947 28 47
BH2 boron dihydride 2 A1 1143 954 0.834 29 48
AlH2 aluminum dihydride 1 A1 1960 1770 0.903 30 49
    2 A1 823 760 0.924 30 50
    3 B2 1974 1807 0.915 30 51
MgF Magnesium monofluoride 1 Σ 779 712 0.914 31 52
MgCl magnesium monochloride 1 Σ 459 462 1.006 32 53
ClO Monochlorine monoxide 1 Σ 869 854 0.982 33 54
PF phosphorus monofluoride 1 Σ 912 847 0.929 34 55
BeOH beryllium hydroxide 2 A' 1312 1246 0.950 35 56
S2 Sulfur diatomic 1 Σg 819 726 0.887 36 57
ClS2 Sulfur chloride 1 A' 598 662 1.106 37 58
    2 A' 528 450 0.852 37 59
    3 A' 241 196 0.812 37 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.

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