return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Vibrations > Scale Factors > Scale factor uncertainty

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
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
MgH magnesium monohydride 1 Σ 1577 1493 0.947 1 1
CH Methylidyne 1 Σ 3029 2861 0.944 2 2
SiH Silylidyne 1 Σ 2164 2043 0.944 3 3
NH Imidogen 1 Σ 3551 3283 0.924 4 4
SiN Silicon nitride 1 Σ 1319 1151 0.873 5 5
PH phosphorus monohydride 1 Σ 2526 2364 0.936 6 6
CP Carbon monophosphide 1 Σ 1453 1240 0.853 7 7
OH Hydroxyl radical 1 Σ 4069 3738 0.918 8 8
LiO lithium oxide 1 Σ 888 815 0.917 9 9
NaO sodium monoxide 1 Σ 525 492 0.938 10 10
HS Mercapto radical 1 Σ 2878 2696 0.937 11 11
BS boron sulfide 1 Σ 1269 1180 0.930 12 12
AlS Aluminum sulfide 1 Σ 681 617 0.906 13 13
S2 Sulfur diatomic 1 Σg 819 726 0.887 14 14
BeF Beryllium monofluoride 1 Σ 1318 1247 0.947 15 15
CF Fluoromethylidyne 1 Σ 1410 1308 0.927 16 16
MgF Magnesium monofluoride 1 Σ 779 712 0.914 17 17
SiF silicon monofluoride 1 Σ 919 857 0.932 18 18
PF phosphorus monofluoride 1 Σ 912 847 0.929 19 19
BeCl beryllium monochloride 1 Σ 856 847 0.990 20 20
CCl carbon monochloride 1 Σ 872 877 1.006 21 21
ClO Monochlorine monoxide 1 Σ 869 854 0.982 22 22
MgCl magnesium monochloride 1 Σ 459 462 1.006 23 23
SiCl Clorosilylidyne 1 Σ 532 536 1.008 24 24
BH2 boron dihydride 2 A1 1143 954 0.834 25 25
AlH2 aluminum dihydride 1 A1 1960 1770 0.903 26 26
    2 A1 823 760 0.924 26 27
    3 B2 1974 1807 0.915 26 28
NH2 Amino radical 1 A1 3627 3219 0.888 27 29
    2 A1 1669 1497 0.897 27 30
    3 B2 3725 3301 0.886 27 31
PH2 Phosphino radical 1 A1 2554 2310 0.905 28 32
    2 A1 1243 1102 0.886 28 33
BeOH beryllium hydroxide 2 A' 1312 1246 0.950 29 34
HCO Formyl radical 1 A' 2976 2434 0.818 30 35
    2 A' 2154 1868 0.867 30 36
    3 A' 1264 1081 0.855 30 37
HO2 Hydroperoxy radical 1 A' 4085 3436 0.841 31 38
    2 A' 1603 1392 0.868 31 39
    3 A' 1252 1098 0.877 31 40
NF2 Difluoroamino radical 1 A1 1270 1075 0.846 32 41
    2 A1 653 573 0.877 32 42
    3 B2 1193 942 0.790 32 43
OClO Chlorine dioxide 1 A1 1070 946 0.883 33 44
    2 A1 508 448 0.882 33 45
    3 B2 1275 1110 0.870 33 46
ClS2 Sulfur chloride 1 A' 598 662 1.106 34 47
    2 A' 528 450 0.852 34 48
    3 A' 241 196 0.812 34 49
SiH3 Silyl radical 1 A1 2340 2136 0.913 35 50
    2 A1 895 728 0.813 35 51
    3 E 2359 2185 0.926 35 52
    4 E 1018 922 0.905 35 53
CF3 Trifluoromethyl radical 1 A1 1220 1089 0.892 36 54
    2 A1 759 701 0.924 36 55
    3 E 1442 1260 0.874 36 56
    4 E 550 509 0.924 36 57
C3H3 Propargyl radical 1 A1 3644 3322 0.912 37 58
    6 B1 761 687 0.903 37 59
    7 B1 495 490 0.990 37 60

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 25 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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