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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/3-21G
Scale factor How many Source
Molecules Vibrations
0.907 ± 0.178 35 56 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
MgH magnesium monohydride 1 Σ 1587 1493 0.941 1 1
CH Methylidyne 1 Σ 2886 2861 0.991 2 2
SiH Silylidyne 1 Σ 2032 2043 1.005 3 3
NH Imidogen 1 Σ 3233 3283 1.015 4 4
SiN Silicon nitride 1 Σ 1245 1151 0.925 5 5
PH phosphorus monohydride 1 Σ 2298 2364 1.028 6 6
CP Carbon monophosphide 1 Σ 1335 1240 0.928 7 7
OH Hydroxyl radical 1 Σ 3633 3738 1.029 8 8
LiO lithium oxide 1 Σ 929 815 0.877 9 9
NaO sodium monoxide 1 Σ 536 492 0.918 10 10
HS Mercapto radical 1 Σ 2596 2696 1.039 11 11
BS boron sulfide 1 Σ 1199 1180 0.984 12 12
SO Sulfur monoxide 1 Σ 1136 1151 1.013 13 13
AlS Aluminum sulfide 1 Σ 571 617 1.081 14 14
S2 Sulfur diatomic 1 Σg 635 726 1.142 15 15
BeF Beryllium monofluoride 1 Σ 1402 1247 0.890 16 16
CF Fluoromethylidyne 1 Σ 1331 1308 0.983 17 17
MgF Magnesium monofluoride 1 Σ 798 712 0.892 18 18
SiF silicon monofluoride 1 Σ 928 857 0.924 19 19
BeCl beryllium monochloride 1 Σ 801 847 1.057 20 20
CCl carbon monochloride 1 Σ 630 877 1.391 21 21
ClO Monochlorine monoxide 1 Σ 796 854 1.072 22 22
MgCl magnesium monochloride 1 Σ 441 462 1.048 23 23
SiCl Clorosilylidyne 1 Σ 432 536 1.239 24 24
BH2 boron dihydride 2 A1 1112 954 0.858 25 25
AlH2 aluminum dihydride 1 A1 1922 1770 0.921 26 26
    2 A1 781 760 0.973 26 27
    3 B2 1938 1807 0.932 26 28
NH2 Amino radical 1 A1 3413 3219 0.943 27 29
    2 A1 1708 1497 0.877 27 30
    3 B2 3509 3301 0.941 27 31
PH2 Phosphino radical 1 A1 2350 2310 0.983 28 32
    2 A1 1222 1102 0.902 28 33
HCO Formyl radical 1 A' 3026 2434 0.805 29 34
    2 A' 2030 1868 0.920 29 35
    3 A' 1249 1081 0.865 29 36
HO2 Hydroperoxy radical 1 A' 3780 3436 0.909 30 37
    2 A' 1496 1392 0.930 30 38
    3 A' 1136 1098 0.966 30 39
NF2 Difluoroamino radical 1 A1 1119 1075 0.961 31 40
    2 A1 543 573 1.055 31 41
    3 B2 1094 942 0.861 31 42
OClO Chlorine dioxide 1 A1 655 946 1.443 32 43
    2 A1 295 448 1.516 32 44
    3 B2 909 1110 1.221 32 45
ClS2 Sulfur chloride 1 A' 469 662 1.413 33 46
    2 A' 431 450 1.044 33 47
    3 A' 180 196 1.090 33 48
SiH3 Silyl radical 1 A1 2269 2136 0.942 34 49
    2 A1 819 728 0.889 34 50
    3 E 2288 2185 0.955 34 51
    4 E 992 922 0.929 34 52
CF3 Trifluoromethyl radical 1 A1 1160 1089 0.939 35 53
    2 A1 709 701 0.989 35 54
    3 E 1451 1260 0.868 35 55
    4 E 520 509 0.978 35 56

How do we calculate the scaling factor? 2015 08 03 12:34

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 20 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 15 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 10 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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