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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CISD/3-21G*
Scale factor How many Source
Molecules Vibrations
0.934 ± 0.026 9 141 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
LiO lithium oxide 1 Σ 891 799 0.896 1 1
NaO sodium monoxide 1 Σ 538     2 2
CS carbon monosulfide 1 Σ 1329 1272 0.957 3 3
SiH2Cl2 dichlorosilane 1 A1 2406 2224 0.924 4 4
    2 A1 1009 954 0.946 4 5
    3 A1 558 527 0.944 4 6
    4 A1 200 188 0.941 4 7
    5 A2 770 710 0.922 4 8
    6 B1 2418 2237 0.925 4 9
    7 B1 630 602 0.955 4 10
    8 B2 947 876 0.925 4 11
    9 B2 628 590 0.939 4 12
CH2CHCH3 Propene 1 A' 3263 3090 0.947 5 13
    2 A' 3195 3013 0.943 5 14
    3 A' 3182 2991 0.940 5 15
    4 A' 3152 2954 0.937 5 16
    5 A' 3084 2871 0.931 5 17
    6 A' 1754 1650 0.941 5 18
    7 A' 1604 1470 0.916 5 19
    8 A' 1542 1420 0.921 5 20
    9 A' 1507 1378 0.915 5 21
    10 A' 1401 1297 0.926 5 22
    11 A' 1248 1171 0.938 5 23
    12 A' 1019 963 0.945 5 24
    13 A' 917 920 1.003 5 25
    14 A' 449 428 0.954 5 26
    15 A" 3135 2954 0.942 5 27
    16 A" 1591 1443 0.907 5 28
    17 A" 1146 1045 0.912 5 29
    18 A" 1064 991 0.931 5 30
    19 A" 994 912 0.918 5 31
    20 A" 607 578 0.952 5 32
    21 A" 187 174 0.928 5 33
CH3CH2NH2 Ethylamine 1 A' 3466 3345 0.965 6 34
    2 A' 3155 2985 0.946 6 35
    3 A' 3110 2840 0.913 6 36
    4 A' 3086 2860 0.927 6 37
    5 A' 1780 1622 0.911 6 38
    6 A' 1608 1487 0.925 6 39
    7 A' 1592 1465 0.920 6 40
    8 A' 1498 1378 0.920 6 41
    9 A' 1442 1397 0.969 6 42
    10 A' 1193 1016 0.851 6 43
    11 A' 1048 1086 1.037 6 44
    12 A' 914 892 0.975 6 45
    13 A' 808 773 0.957 6 46
    14 A' 403 403 1.000 6 47
    15 A" 3557 3412 0.959 6 48
    16 A" 3161 2924 0.925 6 49
    17 A" 3135 2906 0.927 6 50
    18 A" 1605 1455 0.907 6 51
    19 A" 1445 1238 0.857 6 52
    20 A" 1343 1293 0.963 6 53
    21 A" 1053 1117 1.061 6 54
    22 A" 807 816 1.011 6 55
    23 A" 316 259 0.821 6 56
    24 A" 262 218 0.831 6 57
CH3CH2CHO Propanal 1 A' 3193 2981 0.934 7 58
    2 A' 3128 2904 0.928 7 59
    3 A' 3105 2895 0.932 7 60
    4 A' 3018 2809 0.931 7 61
    5 A' 1782 1743 0.978 7 62
    6 A' 1611 1460 0.906 7 63
    7 A' 1572 1416 0.901 7 64
    8 A' 1523 1390 0.913 7 65
    9 A' 1493 1376 0.922 7 66
    10 A' 1420 1335 0.940 7 67
    11 A' 1153 1093 0.948 7 68
    12 A' 1040 993 0.955 7 69
    13 A' 861 848 0.985 7 70
    14 A' 702 668 0.952 7 71
    15 A' 281 271 0.965 7 72
    16 A" 3197 2992 0.936 7 73
    17 A" 3133 2942 0.939 7 74
    18 A" 1613 1451 0.899 7 75
    19 A" 1364 1250 0.916 7 76
    20 A" 1220 1118 0.917 7 77
    21 A" 966 892 0.923 7 78
    22 A" 737 660 0.895 7 79
    23 A" 240 220 0.917 7 80
    24 A" 136 135 0.995 7 81
CH3COOCH3 methyl acetate 1 A' 3250 3035 0.934 8 82
    2 A' 3249 3031 0.933 8 83
    3 A' 3150 2966 0.941 8 84
    4 A' 3146 2964 0.942 8 85
    5 A' 1844 1771 0.960 8 86
    6 A' 1623 1460 0.899 8 87
    7 A' 1588 1440 0.907 8 88
    8 A' 1557 1430 0.919 8 89
    9 A' 1503 1375 0.915 8 90
    10 A' 1314 1248 0.950 8 91
    11 A' 1243 1159 0.933 8 92
    12 A' 1125 1060 0.942 8 93
    13 A' 1015 980 0.966 8 94
    14 A' 850 844 0.993 8 95
    15 A' 654 639 0.977 8 96
    16 A' 418 429 1.027 8 97
    17 A' 276 303 1.099 8 98
    18 A" 3212 3005 0.935 8 99
    19 A" 3210 2994 0.933 8 100
    20 A" 1608 1460 0.908 8 101
    21 A" 1596 1430 0.896 8 102
    22 A" 1220 1187 0.973 8 103
    23 A" 1151 1036 0.900 8 104
    24 A" 618 607 0.982 8 105
    25 A" 174 187 1.073 8 106
    26 A" 116 136 1.177 8 107
    27 A" 105 110 1.048 8 108
C5H8 1,4-Pentadiene 1 A 3289 3080 0.936 9 109
    2 A 3223 3012 0.934 9 110
    3 A 3207 3012 0.939 9 111
    4 A 3102 2900 0.935 9 112
    5 A 1776 1644 0.926 9 113
    6 A 1584 1433 0.905 9 114
    7 A 1558 1413 0.907 9 115
    8 A 1403 1295 0.923 9 116
    9 A 1341 1263 0.942 9 117
    10 A 1150 1120 0.974 9 118
    11 A 1080 995 0.921 9 119
    12 A 1020 918 0.900 9 120
    13 A 949 876 0.923 9 121
    14 A 703 562 0.800 9 122
    15 A 392 421 1.075 9 123
    16 A 318 137 0.430 9 124
    17 A 86 102 1.190 9 125

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 60 1 1 1 1 1 1 1 1 1 1 1 1 1 1
40 50 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 30 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 10 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