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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at MP2=FULL/aug-cc-pVQZ
Scale factor How many Source
Molecules Vibrations
0.956 ± 0.025 25 87 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4514 4401 0.975 1 1
LiH Lithium Hydride 1 Σ 1447 1405 0.971 2 2
Li2 Lithium diatomic 1 Σg 355 351 0.991 3 3
CH Methylidyne 1 Σ 3219 3145 0.977 4 4
N2 Nitrogen diatomic 1 Σg 2217 2359 1.064 5 5
PH phosphorus monohydride 1 Σ 2448 2415 0.986 6 6
OH Hydroxyl radical 1 Σ 3822 3738 0.978 7 7
BeO beryllium oxide 1 Σ 1427 1457 1.021 8 8
CO Carbon monoxide 1 Σ 2137 2170 1.015 9 9
HF Hydrogen fluoride 1 Σ 4149 4138 0.998 10 10
F2 Fluorine diatomic 1 Σg 1009 917 0.909 11 11
HCl Hydrogen chloride 1 Σ 3042 2991 0.983 12 12
AlCl Aluminum monochloride 1 Σ 509 482 0.946 13 13
BeH2 beryllium dihydride 2 Σu 2266 2159 0.953 14 14
    3 Πu 716 698 0.975 14 15
H2O Water 1 A1 3847 3657 0.951 15 16
    2 A1 1636 1595 0.975 15 17
    3 B2 3973 3756 0.945 15 18
CO2 Carbon dioxide 1 Σg 1342 1333 0.993 16 19
    2 Σu 2426 2349 0.968 16 20
    3 Πu 668 667 0.999 16 21
C2H2 Acetylene 1 Σg 3554 3374 0.949 17 22
    2 Σg 1992 1974 0.991 17 23
    3 Σu 3465 3289 0.949 17 24
    4 Πg 663 612 0.923 17 25
    5 Πu 770 730 0.948 17 26
NH3 Ammonia 1 A1 3527 3337 0.946 18 27
    2 A1 1029 950 0.923 18 28
    3 E 3676 3444 0.937 18 29
    4 E 1673 1627 0.972 18 30
H2CO Formaldehyde 1 A1 2986 2782 0.932 19 31
    2 A1 1771 1746 0.986 19 32
    3 A1 1549 1500 0.968 19 33
    4 B1 1204 1167 0.969 19 34
    5 B2 3064 2843 0.928 19 35
    6 B2 1276 1249 0.979 19 36
BF3 Borane, trifluoro- 1 A1' 896 888 0.991 20 37
    2 A2" 699 691 0.988 20 38
    3 E' 1474 1449 0.983 20 39
    4 E' 481 480 0.999 20 40
AlF3 Aluminum trifluoride 1 A1' 716 690 0.964 21 41
    2 A2" 323 297 0.918 21 42
    3 E' 982 935 0.952 21 43
    4 E' 254 263 1.034 21 44
CH4 Methane 1 A1 3081 2917 0.947 22 45
    2 E 1589 1534 0.965 22 46
    3 T2 3220 3019 0.938 22 47
    4 T2 1354 1306 0.964 22 48
C2H4 Ethylene 1 Ag 3206 3026 0.944 23 49
    2 Ag 1689 1623 0.961 23 50
    3 Ag 1387 1342 0.968 23 51
    4 Au 1080 1023 0.947 23 52
    5 B1u 3189 2989 0.937 23 53
    6 B1u 1486 1444 0.971 23 54
    7 B2g 986 940 0.953 23 55
    8 B2u 3306 3105 0.939 23 56
    9 B2u 830 826 0.995 23 57
    10 B3g 3280 3086 0.941 23 58
    11 B3g 1247 1217 0.976 23 59
    12 B3u 989 949 0.960 23 60
C2H6 Ethane 1 A1g 3089 2954 0.956 24 61
    2 A1g 1435 1388 0.967 24 62
    3 A1g 1035 995 0.962 24 63
    4 A1u 317 289 0.913 24 64
    5 A2u 3091 2896 0.937 24 65
    6 A2u 1415 1379 0.975 24 66
    7 Eg 3165 2969 0.938 24 67
    8 Eg 1526 1468 0.962 24 68
    9 Eg 1231 1190 0.966 24 69
    10 Eu 3187 2985 0.937 24 70
    11 Eu 1526 1469 0.962 24 71
    12 Eu 826 822 0.995 24 72
C3H5 Allyl radical 1 A1 3330 3114 0.935 25 73
    2 A1 3222 3048 0.946 25 74
    4 A1 1557 1488 0.956 25 75
    5 A1 1320 1245 0.943 25 76
    6 A1 1075 1066 0.991 25 77
    7 A1 438 427 0.974 25 78
    9 A2 606 549 0.906 25 79
    10 B1 1092 968 0.887 25 80
    11 B1 894 802 0.897 25 81
    12 B1 572 518 0.906 25 82
    13 B2 3329 3105 0.933 25 83
    14 B2 3214 3016 0.939 25 84
    15 B2 1519 1463 0.963 25 85
    16 B2 1433 1389 0.969 25 86
    17 B2 1144 1182 1.034 25 87

How do we calculate the scaling factor? 2015 08 03 12:34

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