National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 19April 2018
NIST Standard Reference Database 101
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XIXIndex of properties
XXH-bond dimers
XXIOddities

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III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at ROHF/cc-pVTZ

Scale factor How many Source
Molecules Vibrations
0.901 ± 0.080 60 159 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
C2H5 Ethyl radical 1 A' 3271 3033 0.927 1 1
    2 A' 3183 2842 0.893 1 2
    5 A' 1588 1440 0.907 1 3
    6 A' 1527 1366 0.895 1 4
    7 A' 1106 1138 1.029 1 5
    9 A' 529 528 0.999 1 6
    10 A" 3367 3112 0.924 1 7
    11 A" 3214 2987 0.929 1 8
    12 A" 1604 1440 0.898 1 9
    13 A" 1302 1175 0.903 1 10
CN Cyano radical 1 Σ 2451 2069 0.844 2 11
C2H Ethynyl radical 1 Σ 3621 3299 0.911 3 12
    2 Σ 2281 1841 0.807 3 13
    3 Π 751 372 0.495 3 14
CH3 Methyl radical 1 A1' 3246 3004 0.926 4 15
    2 A2" 174 606 3.485 4 16
    3 E' 3423 3161 0.923 4 17
    4 E' 1522 1396 0.917 4 18
CF3 Trifluoromethyl radical 1 A1 1221 1089 0.892 5 19
    2 A1 772 701 0.909 5 20
    3 E 1424 1260 0.885 5 21
    4 E 562 509 0.906 5 22
C6H5 phenyl 1 A1 3349 3086 0.922 6 23
    2 A1 3336 3072 0.921 6 24
    3 A1 3311 3037 0.917 6 25
    4 A1 1734 1497 0.864 6 26
    5 A1 1610 1439 0.894 6 27
    6 A1 1264 1151 0.911 6 28
    7 A1 1118 1028 0.919 6 29
    8 A1 1079 998 0.925 6 30
    9 A1 1070 973 0.910 6 31
    10 A1 661 605 0.916 6 32
    11 A2 1093 945 0.864 6 33
    12 A2 933 816 0.874 6 34
    13 A2 449     6 35
    14 B1 1116 990 0.887 6 36
    15 B1 1000 873 0.873 6 37
    16 B1 801 703 0.877 6 38
    17 B1 745 655 0.879 6 39
    18 B1 470 415 0.883 6 40
    19 B2 3344 3070 0.918 6 41
    20 B2 3321 3060 0.921 6 42
    21 B2 1767 1593 0.902 6 43
    22 B2 1581 1432 0.906 6 44
    23 B2 1418 1310 0.924 6 45
    24 B2 1325 1281 0.967 6 46
    25 B2 1199 1159 0.967 6 47
    26 B2 1132 1060 0.936 6 48
    27 B2 650 588 0.904 6 49
CH2 Methylene 1 A1 3259 2806 0.861 7 50
    2 A1 1300 963 0.741 7 51
    3 B2 3468 3190 0.920 7 52
CH2OH Hydroxymethyl radical 1 A 4176 3650 0.874 8 53
    4 A 1607 1459 0.908 8 54
    5 A 1469 1334 0.908 8 55
    6 A 1274 1176 0.923 8 56
    7 A 1150 1048 0.912 8 57
    8 A 884 482 0.545 8 58
    9 A 400 234 0.585 8 59
HCO Formyl radical 1 A' 2944 2434 0.827 9 60
    2 A' 2131 1868 0.877 9 61
    3 A' 1250 1081 0.865 9 62
C2H3 vinyl 1 A' 3376 3141 0.930 10 63
    2 A' 3333 2953 0.886 10 64
    3 A' 3249 2912 0.896 10 65
    5 A' 1508 1360 0.902 10 66
    7 A' 826 674 0.816 10 67
    8 A" 1057 895 0.847 10 68
    9 A" 966 857 0.887 10 69
C3H3 Propargyl radical 1 A1 3620 3322 0.918 11 70
    6 B1 764 687 0.899 11 71
    7 B1 507 490 0.966 11 72
HO2 Hydroperoxy radical 1 A' 4070 3436 0.844 12 73
    2 A' 1607 1392 0.866 12 74
    3 A' 1251 1098 0.877 12 75
CH Methylidyne 1 Σ 3035 2861 0.943 13 76
OH Hydroxyl radical 1 Σ 4053 3738 0.922 14 77
NF2 Difluoroamino radical 1 A1 1271 1075 0.846 15 78
    2 A1 670 573 0.855 15 79
    3 B2 1179 942 0.799 15 80
CF Fluoromethylidyne 1 Σ 1417 1308 0.923 16 81
CCl carbon monochloride 1 Σ 867 877 1.011 17 82
O2 Oxygen diatomic 1 Σg 2004 1580 0.788 18 83
BN boron nitride 1 Σ 1778 1520 0.855 19 84
OClO Chlorine dioxide 1 A1 1138 946 0.831 20 85
    2 A1 543 448 0.824 20 86
    3 B2 1323 1110 0.839 20 87
NO Nitric oxide 1 Σ 2253 1904 0.845 21 88
NO2 Nitrogen dioxide 1 A1 1622 1318 0.813 22 89
    2 A1 855 750 0.877 22 90
    3 B2 1925 1618 0.841 22 91
SiF silicon monofluoride 1 Σ 897 857 0.956 23 92
NS Mononitrogen monosulfide 1 Σ 1343 1219 0.907 24 93
SiN Silicon nitride 1 Σ 1309 1151 0.880 25 94
FO Oxygen monofluoride 1 Σ 1246 1053 0.845 26 95
C4 Carbon tetramer 1 Σg 2321 2057 0.886 27 96
    3 Σu 1292 1549 1.199 27 97
    4 Πg 467 323 0.691 27 98
    5 Πu 212 160 0.756 27 99
BS boron sulfide 1 Σ 1261 1180 0.936 28 100
AlS Aluminum sulfide 1 Σ 681 617 0.906 29 101
PS phosphorus sulfide 1 Σ 823 739 0.898 30 102
CP Carbon monophosphide 1 Σ 1448 1240 0.856 31 103
BO boron monoxide 1 Σ 2097 1885 0.899 32 104
BeH beryllium monohydride 1 Σ 2129 2061 0.968 33 105
PH2 Phosphino radical 1 A1 2507 2310 0.921 34 106
    2 A1 1222 1102 0.902 34 107
SiH3 Silyl radical 1 A1 2297 2136 0.930 35 108
    2 A1 903 728 0.806 35 109
    3 E 2313 2185 0.945 35 110
    4 E 1010 922 0.913 35 111
NH2 Amino radical 1 A1 3612 3219 0.891 36 112
    2 A1 1649 1497 0.908 36 113
    3 B2 3700 3301 0.892 36 114
NH Imidogen 1 Σ 3544 3283 0.926 37 115
SiH Silylidyne 1 Σ 2119 2043 0.964 38 116
DS Mercapto-d 1 Σ 2035 1886 0.927 39 117
SO Sulfur monoxide 1 Σ 1372 1151 0.839 40 118
BO2 Boron dioxide 1 Σg 1193 1278 1.071 41 119
    2 Σu 2694 1056 0.392 41 120
    3 Πu 536 448 0.836 41 121
HS Mercapto radical 1 Σ 2834 2696 0.952 42 122
HSe Selenium monohydride 1 Σ 2560 2400 0.937 43 123
SiCl Clorosilylidyne 1 Σ 528 536 1.015 44 124
NF nitrogen fluoride 1 Σ 1259 1141 0.906 45 125
PH phosphorus monohydride 1 Σ 2482 2364 0.952 46 126
BH2 boron dihydride 2 A1 1125 954 0.847 47 127
PO Phosphorus monoxide 1 Σ 1434 1233 0.860 48 128
AlO Aluminum monoxide 1 Σ 783 979 1.250 49 129
AlH2 aluminum dihydride 1 A1 1943 1770 0.911 50 130
    2 A1 820 760 0.926 50 131
    3 B2 1953 1807 0.925 50 132
ClO Monochlorine monoxide 1 Σ 871 854 0.980 51 133
PF phosphorus monofluoride 1 Σ 903 847 0.938 52 134
ClOO chloroperoxy radical 1 A' 1198 1443 1.205 53 135
    2 A' 810 414 0.511 53 136
    3 A' 486 201 0.414 53 137
S2 Sulfur diatomic 1 Σg 818 726 0.887 54 138
AlN Aluminum nitride 1 Σ 719 747 1.039 55 139
ClS2 Sulfur chloride 1 A' 595 662 1.112 56 140
    2 A' 531 450 0.847 56 141
    3 A' 239 196 0.819 56 142

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.

70
60
50
40
30
20
10
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