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/6-311G*
Scale factor How many Source
Molecules Vibrations
0.856 ± 0.159 36 57 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
MgH magnesium monohydride 1 Σ 1580 1493 0.945 1 1
CH Methylidyne 1 Σ 3065 2861 0.933 2 2
SiH Silylidyne 1 Σ 2138 2043 0.955 3 3
NH Imidogen 1 Σ 3571 3283 0.919 4 4
SiN Silicon nitride 1 Σ 1326 1151 0.869 5 5
PH phosphorus monohydride 1 Σ 2498 2364 0.946 6 6
CP Carbon monophosphide 1 Σ 1461 1240 0.849 7 7
OH Hydroxyl radical 1 Σ 4054 3738 0.922 8 8
LiO lithium oxide 1 Σ 868 815 0.938 9 9
NaO sodium monoxide 1 Σ 524 492 0.939 10 10
HS Mercapto radical 1 Σ 2810 2696 0.959 11 11
BS boron sulfide 1 Σ 1263 1180 0.934 12 12
AlS Aluminum sulfide 1 Σ 683 617 0.903 13 13
S2 Sulfur diatomic 1 Σg 801 726 0.906 14 14
BeF Beryllium monofluoride 1 Σ 1273 1247 0.980 15 15
CF Fluoromethylidyne 1 Σ 1403 1308 0.932 16 16
MgF Magnesium monofluoride 1 Σ 743 712 0.958 17 17
SiF silicon monofluoride 1 Σ 886 857 0.968 18 18
PF phosphorus monofluoride 1 Σ 869 847 0.974 19 19
BeCl beryllium monochloride 1 Σ 844 847 1.003 20 20
CCl carbon monochloride 1 Σ 863 877 1.016 21 21
ClO Monochlorine monoxide 1 Σ 841 854 1.015 22 22
MgCl magnesium monochloride 1 Σ 456 462 1.013 23 23
SiCl Clorosilylidyne 1 Σ 517 536 1.037 24 24
BH2 boron dihydride 2 A1 1125 954 0.848 25 25
AlH2 aluminum dihydride 1 A1 1975 1770 0.896 26 26
    2 A1 823 760 0.924 26 27
    3 B2 1986 1807 0.910 26 28
NH2 Amino radical 1 A1 3636 3219 0.885 27 29
    2 A1 1718 1497 0.872 27 30
    3 B2 3722 3301 0.887 27 31
PH2 Phosphino radical 1 A1 2529 2310 0.913 28 32
    2 A1 1254 1102 0.879 28 33
BeOH beryllium hydroxide 2 A' 1319 1246 0.944 29 34
HCO Formyl radical 1 A' 2970 2434 0.820 30 35
    2 A' 2147 1868 0.870 30 36
    3 A' 1269 1081 0.852 30 37
HO2 Hydroperoxy radical 1 A' 4090 3436 0.840 31 38
    2 A' 1659 1392 0.839 31 39
    3 A' 1269 1098 0.865 31 40
NF2 Difluoroamino radical 1 A1 1276 1075 0.843 32 41
    2 A1 673 573 0.852 32 42
    3 B2 1189 942 0.793 32 43
ClS2 Sulfur chloride 1 A' 567 662 1.168 33 44
    2 A' 519 450 0.866 33 45
    3 A' 239 196 0.822 33 46
SiH3 Silyl radical 1 A1 2329 2136 0.917 34 47
    2 A1 897 728 0.812 34 48
    3 E 2340 2185 0.934 34 49
    4 E 1017 922 0.907 34 50
CF3 Trifluoromethyl radical 1 A1 1214 1089 0.897 35 51
    2 A1 766 701 0.915 35 52
    3 E 1421 1260 0.887 35 53
    4 E 561 509 0.906 35 54
C3H3 Propargyl radical 1 A1 3632 3322 0.915 36 55
    6 B1 737 687 0.932 36 56
    7 B1 472 490 1.038 36 57

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