return to home page

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
0.907 ± 0.031 41 76 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
C3H5 Allyl radical 1 A1 3422 3114 0.910 1 1
    2 A1 3337 3048 0.914 1 2
    4 A1 1648 1488 0.903 1 3
    5 A1 1342 1245 0.928 1 4
    6 A1 1075 1066 0.991 1 5
    7 A1 451 427 0.946 1 6
    9 A2 572 549 0.959 1 7
    10 B1 1035 968 0.935 1 8
    11 B1 800 802 1.002 1 9
    12 B1 547 518 0.946 1 10
    13 B2 3418 3105 0.908 1 11
    14 B2 3324 3016 0.907 1 12
    15 B2 1638 1463 0.893 1 13
    16 B2 1538 1389 0.903 1 14
    17 B2 1252 1182 0.944 1 15
CF3 Trifluoromethyl radical 1 A1 1220 1089 0.892 2 16
    2 A1 759 701 0.924 2 17
    3 E 1442 1260 0.874 2 18
    4 E 550 509 0.924 2 19
HCO Formyl radical 1 A' 3010 2434 0.809 3 20
    2 A' 2155 1868 0.867 3 21
    3 A' 1273 1081 0.849 3 22
C3H3 Propargyl radical 1 A1 3664 3322 0.907 4 23
    6 B1 755 687 0.911 4 24
    7 B1 483 490 1.014 4 25
HO2 Hydroperoxy radical 1 A' 4021 3436 0.854 5 26
    2 A' 1625 1392 0.856 5 27
    3 A' 1250 1098 0.878 5 28
CH Methylidyne 1 Σ 3066 2861 0.933 6 29
OH Hydroxyl radical 1 Σ 4013 3738 0.931 7 30
NF2 Difluoroamino radical 1 A1 1270 1075 0.846 8 31
    2 A1 653 573 0.877 8 32
    3 B2 1193 942 0.790 8 33
CF Fluoromethylidyne 1 Σ 1410 1308 0.927 9 34
CCl carbon monochloride 1 Σ 872 877 1.006 10 35
OClO Chlorine dioxide 1 A1 1070 946 0.883 11 36
    2 A1 508 448 0.882 11 37
    3 B2 1275 1110 0.870 11 38
SiF silicon monofluoride 1 Σ 919 857 0.932 12 39
SiN Silicon nitride 1 Σ 1319 1151 0.873 13 40
LiO lithium oxide 1 Σ 888 815 0.917 14 41
BS boron sulfide 1 Σ 1269 1180 0.930 15 42
AlS Aluminum sulfide 1 Σ 681 617 0.906 16 43
CP Carbon monophosphide 1 Σ 1453 1240 0.853 17 44
NaO sodium monoxide 1 Σ 525 492 0.938 18 45
BO boron monoxide 1 Σ 2112 1885 0.892 19 46
Si2 Silicon diatomic 1 Σg 594 511 0.861 20 47
BeF Beryllium monofluoride 1 Σ 1318 1247 0.947 21 48
BeH beryllium monohydride 1 Σ 2168 2061 0.951 22 49
PH2 Phosphino radical 1 A1 2582 2310 0.895 23 50
    2 A1 1258 1102 0.876 23 51
SiH3 Silyl radical 1 A1 2362 2136 0.904 24 52
    2 A1 899 728 0.809 24 53
    3 E 2381 2185 0.918 24 54
    4 E 1017 922 0.907 24 55
NH2 Amino radical 1 A1 3623 3219 0.888 25 56
    2 A1 1715 1497 0.873 25 57
    3 B2 3725 3301 0.886 25 58
NH Imidogen 1 Σ 3568 3283 0.920 26 59
SiH Silylidyne 1 Σ 2182 2043 0.936 27 60
BeCl beryllium chloride 1 Σ 856 847 0.990 28 61
SH Mercapto radical 1 Σ 2899 2696 0.930 29 62
SiCl Clorosilylidyne 1 Σ 532 536 1.008 30 63
NF nitrogen fluoride 1 Σ 1266 1141 0.902 31 64
PH phosphorus monohydride 1 Σ 2551 2364 0.927 32 65
MgH magnesium monohydride 1 Σ 1577 1493 0.947 33 66
BH2 boron dihydride 2 A1 1150 954 0.829 34 67
AlH2 aluminum dihydride 1 A1 1970 1770 0.899 35 68
    2 A1 821 760 0.926 35 69
    3 B2 1984 1807 0.911 35 70
MgF Magnesium monofluoride 1 Σ 779 712 0.914 36 71
MgCl magnesium monochloride 1 Σ 459 462 1.006 37 72
ClO Monochlorine monoxide 1 Σ 869 854 0.982 38 73
PF phosphorus monofluoride 1 Σ 912 847 0.929 39 74
PCl phosphorus chloride 1 Σ 557 577 1.035 40 75
BeOH beryllium hydroxide 2 A' 1303 1246 0.956 41 76
S2 Sulfur diatomic 1 Σg 819 726 0.887 42 77
ClS2 Sulfur chloride 1 A' 598 662 1.106 43 78
    2 A' 528 450 0.852 43 79
    3 A' 241 196 0.812 43 80

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.

35
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