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

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
H2CO Formaldehyde 1 A1 2986 2782 0.932 1 1
    2 A1 1771 1746 0.986 1 2
    3 A1 1549 1500 0.968 1 3
    4 B1 1204 1167 0.969 1 4
    5 B2 3064 2843 0.928 1 5
    6 B2 1276 1249 0.979 1 6
CH4 Methane 1 A1 3081 2917 0.947 2 7
    2 E 1589 1534 0.965 2 8
    3 T2 3220 3019 0.938 2 9
    4 T2 1354 1306 0.964 2 10
C2H6 Ethane 1 A1g 3089 2896 0.938 3 11
    2 A1g 1435 1388 0.967 3 12
    3 A1g 1035 995 0.962 3 13
    4 A1u 317 289 0.913 3 14
    5 A2u 3091 2915 0.943 3 15
    6 A2u 1415 1370 0.968 3 16
    7 Eg 3165 2969 0.938 3 17
    8 Eg 1526 1468 0.962 3 18
    9 Eg 1231 1190 0.966 3 19
    10 Eu 3187 2974 0.933 3 20
    11 Eu 1526 1460 0.957 3 21
    12 Eu 826 822 0.995 3 22
C2H4 Ethylene 1 Ag 3206 3026 0.944 4 23
    2 Ag 1689 1623 0.961 4 24
    3 Ag 1387 1342 0.968 4 25
    4 Au 1080 1023 0.947 4 26
    5 B1u 3189 2989 0.937 4 27
    6 B1u 1486 1444 0.971 4 28
    7 B2g 986 940 0.953 4 29
    8 B2u 3306 3105 0.939 4 30
    9 B2u 830 826 0.995 4 31
    10 B3g 3280 3086 0.941 4 32
    11 B3g 1247 1217 0.976 4 33
    12 B3u 989 949 0.960 4 34
C2H2 Acetylene 1 Σg 3554 3374 0.949 5 35
    2 Σg 1992 1974 0.991 5 36
    3 Σu 3465 3289 0.949 5 37
    4 Πg 663 612 0.923 5 38
    5 Πu 770 730 0.948 5 39
CO2 Carbon dioxide 1 Σg 1342 1333 0.993 6 40
    2 Σu 2426 2349 0.968 6 41
    3 Πu 668 667 0.999 6 42
CO Carbon monoxide 1 Σ 2137 2170 1.015 7 43
BeO beryllium oxide 1 Σ 1427 1457 1.021 8 44
H2 Hydrogen diatomic 1 Σg 4514 4401 0.975 9 45
C3H5 Allyl radical 1 A1 3330 3114 0.935 10 46
    2 A1 3222 3048 0.946 10 47
    4 A1 1557 1488 0.956 10 48
    5 A1 1320 1245 0.943 10 49
    6 A1 1075 1066 0.991 10 50
    7 A1 438 427 0.974 10 51
    9 A2 606 549 0.906 10 52
    10 B1 1092 968 0.887 10 53
    11 B1 894 802 0.897 10 54
    12 B1 572 518 0.906 10 55
    13 B2 3329 3105 0.933 10 56
    14 B2 3214 3016 0.939 10 57
    15 B2 1519 1463 0.963 10 58
    16 B2 1433 1389 0.969 10 59
    17 B2 1144 1182 1.034 10 60
CH Methylidyne 1 Σ 3219 3145 0.977 11 61
OH Hydroxyl radical 1 Σ 3822 3738 0.978 12 62
LiH Lithium Hydride 1 Σ 1447 1405 0.971 13 63
BF3 Borane, trifluoro- 1 A1' 896 888 0.991 14 64
    2 A2" 699 691 0.988 14 65
    3 E' 1474 1449 0.983 14 66
    4 E' 481 480 0.999 14 67
HCl Hydrogen chloride 1 Σ 3042 2991 0.983 15 68
HF Hydrogen fluoride 1 Σ 4149 4138 0.998 16 69
NH3 Ammonia 1 A1 3527 3337 0.946 17 70
    2 A1 1029 950 0.923 17 71
    3 E 3676 3444 0.937 17 72
    4 E 1673 1627 0.972 17 73
N2 Nitrogen diatomic 1 Σg 2217 2359 1.064 18 74
H2O Water 1 A1 3847 3657 0.951 19 75
    2 A1 1636 1595 0.975 19 76
    3 B2 3973 3756 0.945 19 77
F2 Fluorine diatomic 1 Σg 1009 917 0.909 20 78
AlF3 Aluminum trifluoride 1 A1' 716 690 0.964 21 79
    2 A2" 323 297 0.918 21 80
    3 E' 982 935 0.952 21 81
    4 E' 254 263 1.034 21 82
BeH2 beryllium dihydride 2 Σu 2266 2159 0.953 22 83
    3 Πu 716 698 0.975 22 84
AlCl Aluminum monochloride 1 Σ 509 482 0.946 23 85
PH phosphorus monohydride 1 Σ 2448 2415 0.986 24 86
Li2 Lithium diatomic 1 Σg 355 351 0.991 25 87

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.

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