return to home page Computational Chemistry Comparison and Benchmark DataBase Release 21 (August 2020) 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 CCD/6-311G**
Scale factor How many Source
Molecules Vibrations
0.955 ± 0.017 32 169 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4436 4161 0.938 1 1
LiH Lithium Hydride 1 Σ 1418 1360 0.959 2 2
Li2 Lithium diatomic 1 Σg 350 346 0.988 3 3
Na2 Sodium diatomic 1 Σg 156 158 1.013 4 4
CH Methylidyne 1 Σ 3159     5 5
N2 Nitrogen diatomic 1 Σg 2441 2330 0.954 6 6
PH phosphorus monohydride 1 Σ 2400 2276 0.948 7 7
    1 Σ 2426 2319 0.956 7 8
OH Hydroxyl radical 1 Σ 3820 3570 0.934 8 9
CO Carbon monoxide 1 Σ 2267 2143 0.945 9 10
SO Sulfur monoxide 1 Σ 1178 1138 0.966 10 11
    1 Σ 1119 1054 0.942 10 12
HF Hydrogen fluoride 1 Σ 4279 3961 0.926 11 13
F2 Fluorine diatomic 1 Σg 935 894 0.956 12 14
HCl Hydrogen chloride 1 Σ 3060 2886 0.943 13 15
AlCl Aluminum monochloride 1 Σ 493 478 0.969 14 16
BeH2 beryllium dihydride 2 Σu 2264 2159 0.954 15 17
    3 Πu 693 698 1.008 15 18
H2O Water 1 A1 3923 3657 0.932 16 19
    2 A1 1692 1595 0.942 16 20
    3 B2 4017 3756 0.935 16 21
CO2 Carbon dioxide 1 Σg 1415 1333 0.942 17 22
    2 Σu 2484 2349 0.946 17 23
    3 Πu 691 667 0.966 17 24
SO2 Sulfur dioxide 1 A1 1218 1151 0.945 18 25
    2 A1 537 518 0.964 18 26
    3 B2 1428 1362 0.954 18 27
C2H2 Acetylene 1 Σg 3544 3374 0.952 19 28
    2 Σg 2049 1974 0.964 19 29
    3 Σu 3443 3289 0.955 19 30
    4 Πg 603 612 1.015 19 31
    5 Πu 785 730 0.930 19 32
NH3 Ammonia 1 A1 3516 3337 0.949 20 33
    2 A1 1145 950 0.829 20 34
    3 E 3645 3444 0.945 20 35
    4 E 1687 1627 0.964 20 36
H2CO Formaldehyde 1 A1 2961 2782 0.939 21 37
    2 A1 1852 1746 0.943 21 38
    3 A1 1577 1500 0.951 21 39
    4 B1 1215 1167 0.961 21 40
    5 B2 3028 2843 0.939 21 41
    6 B2 1300 1249 0.961 21 42
BF3 Borane, trifluoro- 1 A1' 897 888 0.990 22 43
    2 A2" 719 691 0.961 22 44
    3 E' 1486 1449 0.975 22 45
    4 E' 491 480 0.977 22 46
AlF3 Aluminum trifluoride 1 A1' 709 690 0.973 23 47
    2 A2" 307 297 0.968 23 48
    3 E' 993 935 0.941 23 49
    4 E' 250 263 1.054 23 50
CH4 Methane 1 A1 3056 2917 0.955 24 51
    2 E 1576 1534 0.973 24 52
    3 T2 3180 3019 0.949 24 53
    4 T2 1370 1306 0.954 24 54
C2H4 Ethylene 1 Ag 3180 3026 0.952 25 55
    2 Ag 1705 1623 0.952 25 56
    3 Ag 1389 1342 0.967 25 57
    4 Au 1059 1023 0.966 25 58
    5 B1u 3161 2989 0.946 25 59
    6 B1u 1489 1444 0.969 25 60
    7 B2g 932 940 1.009 25 61
    8 B2u 3269 3105 0.950 25 62
    9 B2u 832 826 0.992 25 63
    10 B3g 3243 3086 0.952 25 64
    11 B3g 1243 1217 0.979 25 65
    12 B3u 974 949 0.975 25 66
C3H2N2 Malononitrile 1 A1 3103 2935 0.946 26 67
    2 A1 2382 2275 0.955 26 68
    3 A1 1485 1395 0.939 26 69
    4 A1 915 890 0.973 26 70
    5 A1 588 582 0.990 26 71
    6 A1 148 167 1.127 26 72
    7 A2 1268 1220 0.962 26 73
    8 A2 368 367 0.999 26 74
    9 B1 3150 2968 0.942 26 75
    10 B1 958 933 0.973 26 76
    11 B1 340 337 0.992 26 77
    12 B2 2384 2275 0.954 26 78
    13 B2 1374 1318 0.960 26 79
    14 B2 1006 982 0.976 26 80
    15 B2 371 366 0.987 26 81
C2H6 Ethane 1 A1g 3065 2954 0.964 27 82
    2 A1g 1460 1388 0.951 27 83
    3 A1g 1029 995 0.967 27 84
    4 A1u 326 289 0.886 27 85
    5 A2u 3063 2896 0.946 27 86
    6 A2u 1431 1379 0.964 27 87
    7 Eg 3127 2969 0.950 27 88
    8 Eg 1525 1468 0.963 27 89
    9 Eg 1246 1190 0.955 27 90
    10 Eu 3149 2985 0.948 27 91
    11 Eu 1529 1469 0.961 27 92
    12 Eu 834 822 0.985 27 93
C3H5 Allyl radical 1 A1 3286 3114 0.948 28 94
    2 A1 3189 3048 0.956 28 95
    4 A1 1550 1488 0.960 28 96
    5 A1 1299 1245 0.959 28 97
    6 A1 1057 1066 1.009 28 98
    7 A1 433 427 0.985 28 99
    9 A2 575 549 0.954 28 100
    10 B1 1032 968 0.938 28 101
    11 B1 797 802 1.006 28 102
    12 B1 544 518 0.952 28 103
    13 B2 3283 3105 0.946 28 104
    14 B2 3178 3016 0.949 28 105
    15 B2 1515 1463 0.965 28 106
    16 B2 1428 1389 0.973 28 107
    17 B2 1144 1182 1.033 28 108
C3H6 Cyclopropane 1 A1' 3177 3038 0.956 29 109
    2 A1' 1558 1479 0.949 29 110
    3 A1' 1240 1188 0.958 29 111
    4 A1" 1183 1126 0.951 29 112
    5 A2' 1116 1070 0.959 29 113
    6 A2" 3271 3103 0.949 29 114
    7 A2" 873 854 0.978 29 115
    8 E' 3166 3025 0.955 29 116
    9 E' 1499 1438 0.959 29 117
    10 E' 1103 1029 0.933 29 118
    11 E' 915 866 0.946 29 119
    12 E" 3251 3082 0.948 29 120
    13 E" 1240 1188 0.958 29 121
    14 E" 763 739 0.968 29 122
CH2CHCH3 Propene 1 A' 3255 3090 0.949 30 123
    2 A' 3174 3013 0.949 30 124
    3 A' 3161 2991 0.946 30 125
    4 A' 3140 2954 0.941 30 126
    5 A' 3054 2871 0.940 30 127
    6 A' 1735 1650 0.951 30 128
    7 A' 1520 1470 0.967 30 129
    8 A' 1474 1420 0.963 30 130
    9 A' 1434 1378 0.961 30 131
    10 A' 1333 1297 0.973 30 132
    11 A' 1205 1171 0.972 30 133
    12 A' 955 963 1.008 30 134
    13 A' 942 920 0.977 30 135
    14 A' 426 428 1.006 30 136
    15 A" 3118 2954 0.947 30 137
    16 A" 1504 1443 0.959 30 138
    17 A" 1083 1045 0.964 30 139
    18 A" 1024 991 0.968 30 140
    19 A" 926 912 0.985 30 141
    20 A" 584 578 0.989 30 142
    21 A" 194 174 0.896 30 143
CH3CHClCH3 Propane, 2-chloro- 1 A' 3165 3005 0.950 31 144
    2 A' 3149 2955 0.938 31 145
    3 A' 3122 2927 0.937 31 146
    4 A' 3067 2878 0.938 31 147
    5 A' 1526 1472 0.964 31 148
    6 A' 1519 1454 0.957 31 149
    7 A' 1455 1390 0.955 31 150
    8 A' 1352 1270 0.940 31 151
    9 A' 1216 1163 0.956 31 152
    10 A' 1116 1065 0.954 31 153
    11 A' 932 888 0.953 31 154
    12 A' 676 633 0.936 31 155
    13 A' 432 418 0.969 31 156
    14 A' 347 336 0.968 31 157
    15 A' 290 253 0.873 31 158
    16 A" 3160 2997 0.948 31 159
    17 A" 3141 2985 0.950 31 160
    18 A" 3063 2947 0.962 31 161
    19 A" 1508 1472 0.976 31 162
    20 A" 1506 1454 0.965 31 163
    21 A" 1443 1377 0.954 31 164
    22 A" 1382 1334 0.965 31 165
    23 A" 1178 1123 0.953 31 166
    24 A" 977 972 0.994 31 167
    25 A" 957 936 0.978 31 168
    26 A" 335 317 0.947 31 169
    27 A" 253 276 1.093 31 170

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.

40 140 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 120 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 100 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 80 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 60 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 20 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