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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/6-31G*
Scale factor How many Source
Molecules Vibrations
0.890 ± 0.031 47 82 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
BeH beryllium monohydride 1 Σ 2168 1987 0.916 1 1
MgH magnesium monohydride 1 Σ 1577 1432 0.908 2 2
CH Methylidyne 1 Σ 3066 2733 0.891 3 3
SiH Silylidyne 1 Σ 2182 1971 0.903 4 4
NH Imidogen 1 Σ 3568 3126 0.876 5 5
CN Cyano radical 1 Σ 2474 2042 0.825 6 6
SiN Silicon nitride 1 Σ 1319 1138 0.863 7 7
PH phosphorus monohydride 1 Σ 2551 2276 0.892 8 8
CP Carbon monophosphide 1 Σ 1453 1226 0.844 9 9
OH Hydroxyl radical 1 Σ 4013 3570 0.890 10 10
LiO lithium oxide 1 Σ 888 799 0.900 11 11
BO boron monoxide 1 Σ 2112 1862 0.881 12 12
NaO sodium monoxide 1 Σ 525     13 13
HS Mercapto radical 1 Σ 2899 2599 0.896 14 14
BS boron sulfide 1 Σ 1269 1167 0.920 15 15
SO Sulfur monoxide 1 Σ 1318 1138 0.864 16 16
AlS Aluminum sulfide 1 Σ 681 610 0.896 17 17
S2 Sulfur diatomic 1 Σg 819 720 0.880 18 18
BeF Beryllium monofluoride 1 Σ 1318     19 19
CF Fluoromethylidyne 1 Σ 1410 1286 0.912 20 20
NF nitrogen fluoride 1 Σ 1266 1123 0.888 21 21
MgF Magnesium monofluoride 1 Σ 779     22 22
SiF silicon monofluoride 1 Σ 919 848 0.922 23 23
PF phosphorus monofluoride 1 Σ 912 838 0.919 24 24
SF Monosulfur monofluoride 1 Σ 921 829 0.900 25 25
BeCl beryllium monochloride 1 Σ 856 847 0.990 26 26
CCl carbon monochloride 1 Σ 872 866 0.993 27 27
ClF Chlorine monofluoride 1 Σ 914 773 0.846 28 28
MgCl magnesium monochloride 1 Σ 459     29 29
SiCl Clorosilylidyne 1 Σ 532 531 0.999 30 30
PCl phosphorus chloride 1 Σ 557 547 0.981 31 31
SCl sulfur monochloride 1 Σ 595 577 0.969 32 32
BH2 boron dihydride 2 A1 1150 954 0.829 33 33
AlH2 aluminum dihydride 1 A1 1970 1770 0.899 34 34
    2 A1 821 760 0.926 34 35
    3 B2 1984 1807 0.911 34 36
SiH2 silicon dihydride 1 A1 2217 1996 0.900 35 37
    2 A1 1131 999 0.884 35 38
    3 B2 2206 1993 0.903 35 39
PH2 Phosphino radical 1 A1 2582 2310 0.895 36 40
    2 A1 1258 1102 0.876 36 41
BeOH beryllium monohydroxide 2 A' 1303 1246 0.956 37 42
HCO Formyl radical 1 A' 3010 2434 0.809 38 43
    2 A' 2155 1868 0.867 38 44
    3 A' 1273 1081 0.849 38 45
HO2 Hydroperoxy radical 1 A' 4021 3436 0.854 39 46
    2 A' 1625 1392 0.856 39 47
    3 A' 1250 1098 0.878 39 48
NF2 Difluoroamino radical 1 A1 1270 1075 0.846 40 49
    2 A1 653 573 0.877 40 50
    3 B2 1193 942 0.790 40 51
OClO Chlorine dioxide 1 A1 1070 946 0.883 41 52
    2 A1 508 448 0.882 41 53
    3 B2 1275 1110 0.870 41 54
ClS2 Sulfur chloride 1 A' 598 662 1.106 42 55
    2 A' 528 450 0.852 42 56
    3 A' 241 196 0.812 42 57
SiH3 Silyl radical 1 A1 2362 2136 0.904 43 58
    2 A1 899 728 0.810 43 59
    3 E 2381 2185 0.918 43 60
    4 E 1017 922 0.907 43 61
CF3 Trifluoromethyl radical 1 A1 1220 1089 0.892 44 62
    2 A1 759 701 0.924 44 63
    3 E 1442 1260 0.874 44 64
    4 E 550 509 0.924 44 65
C3H3 Propargyl radical 1 A1 3664 3322 0.907 45 66
    6 B1 755 687 0.911 45 67
    7 B1 483 490 1.014 45 68
C3H5 Allyl radical 1 A1 3422 3114 0.910 46 69
    2 A1 3337 3048 0.914 46 70
    4 A1 1648 1488 0.903 46 71
    5 A1 1342 1245 0.928 46 72
    6 A1 1075 1066 0.991 46 73
    7 A1 451 427 0.946 46 74
    9 A2 572 549 0.959 46 75
    10 B1 1035 968 0.935 46 76
    11 B1 800 802 1.002 46 77
    12 B1 547 518 0.946 46 78
    13 B2 3418 3105 0.908 46 79
    14 B2 3324 3016 0.907 46 80
    15 B2 1638 1463 0.893 46 81
    16 B2 1538 1389 0.903 46 82
    17 B2 1252 1182 0.944 46 83

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.

40 45 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 40 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 35 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 30 1 1 1 1 1 1 1 1 1 1 1 1 1 1
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