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 MP2=FULL/aug-cc-pVQZ
Scale factor How many Source
Molecules Vibrations
0.956 ± 0.025 25 87 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2 Hydrogen diatomic 1 Σg 4514 4161 0.922 1 1
LiH Lithium Hydride 1 Σ 1447 1360 0.940 2 2
Li2 Lithium diatomic 1 Σg 355 346 0.976 3 3
CH Methylidyne 1 Σ 3219     4 4
N2 Nitrogen diatomic 1 Σg 2217 2330 1.051 5 5
PH phosphorus monohydride 1 Σ 2429 2276 0.937 6 6
    1 Σ 2448 2319 0.947 6 7
OH Hydroxyl radical 1 Σ 3822 3570 0.934 7 8
BeO beryllium oxide 1 Σ 1427 1435 1.005 8 9
CO Carbon monoxide 1 Σ 2137 2143 1.003 9 10
HF Hydrogen fluoride 1 Σ 4148 3961 0.955 10 11
F2 Fluorine diatomic 1 Σg 1009 894 0.886 11 12
HCl Hydrogen chloride 1 Σ 3042 2886 0.949 12 13
AlCl Aluminum monochloride 1 Σ 509 478 0.938 13 14
BeH2 beryllium dihydride 2 Σu 2266 2159 0.953 14 15
    3 Πu 716 698 0.975 14 16
H2O Water 1 A1 3850 3657 0.950 15 17
    2 A1 1636 1595 0.975 15 18
    3 B2 3975 3756 0.945 15 19
CO2 Carbon dioxide 1 Σg 1342 1333 0.993 16 20
    2 Σu 2426 2349 0.968 16 21
    3 Πu 668 667 0.999 16 22
C2H2 Acetylene 1 Σg 3557 3374 0.949 17 23
    2 Σg 1993 1974 0.991 17 24
    3 Σu 3468 3289 0.948 17 25
    4 Πg 661 612 0.926 17 26
    5 Πu 768 730 0.951 17 27
NH3 Ammonia 1 A1 3527 3337 0.946 18 28
    2 A1 1029 950 0.923 18 29
    3 E 3677 3444 0.937 18 30
    4 E 1673 1627 0.972 18 31
H2CO Formaldehyde 1 A1 2986 2782 0.932 19 32
    2 A1 1771 1746 0.986 19 33
    3 A1 1549 1500 0.968 19 34
    4 B1 1204 1167 0.969 19 35
    5 B2 3063 2843 0.928 19 36
    6 B2 1276 1249 0.979 19 37
BF3 Borane, trifluoro- 1 A1' 896 888 0.991 20 38
    2 A2" 699 691 0.988 20 39
    3 E' 1474 1449 0.983 20 40
    4 E' 481 480 0.999 20 41
AlF3 Aluminum trifluoride 1 A1' 716 690 0.964 21 42
    2 A2" 323 297 0.918 21 43
    3 E' 982 935 0.952 21 44
    4 E' 254 263 1.034 21 45
CH4 Methane 1 A1 3081 2917 0.947 22 46
    2 E 1589 1534 0.965 22 47
    3 T2 3220 3019 0.937 22 48
    4 T2 1354 1306 0.964 22 49
C2H4 Ethylene 1 Ag 3206 3026 0.944 23 50
    2 Ag 1689 1623 0.961 23 51
    3 Ag 1387 1342 0.968 23 52
    4 Au 1080 1023 0.947 23 53
    5 B1u 3189 2989 0.937 23 54
    6 B1u 1486 1444 0.971 23 55
    7 B2g 986 940 0.953 23 56
    8 B2u 3306 3105 0.939 23 57
    9 B2u 830 826 0.995 23 58
    10 B3g 3280 3086 0.941 23 59
    11 B3g 1247 1217 0.976 23 60
    12 B3u 989 949 0.960 23 61
C2H6 Ethane 1 A1g 3089 2954 0.956 24 62
    2 A1g 1435 1388 0.968 24 63
    3 A1g 1034 995 0.962 24 64
    4 A1u 316 289 0.914 24 65
    5 A2u 3091 2896 0.937 24 66
    6 A2u 1415 1379 0.975 24 67
    7 Eg 3165 2969 0.938 24 68
    8 Eg 1526 1468 0.962 24 69
    9 Eg 1231 1190 0.966 24 70
    10 Eu 3187 2985 0.937 24 71
    11 Eu 1526 1469 0.962 24 72
    12 Eu 826 822 0.995 24 73
C3H5 Allyl radical 1 A1 3330 3114 0.935 25 74
    2 A1 3222 3048 0.946 25 75
    4 A1 1557 1488 0.956 25 76
    5 A1 1320 1245 0.943 25 77
    6 A1 1075 1066 0.991 25 78
    7 A1 438 427 0.974 25 79
    9 A2 606 549 0.906 25 80
    10 B1 1092 968 0.887 25 81
    11 B1 894 802 0.897 25 82
    12 B1 572 518 0.906 25 83
    13 B2 3329 3105 0.933 25 84
    14 B2 3214 3016 0.939 25 85
    15 B2 1519 1463 0.963 25 86
    16 B2 1433 1389 0.969 25 87
    17 B2 1144 1182 1.034 25 88

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