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Vibrational frequency scaling factors


Calculated vibrational frequencies ("theory" in table) are calculated at CCSD(T)=FULL/cc-pCVTZ
Scale factor How many Source
Molecules Vibrations
0.966 ± 0.019 47 122 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
LiH Lithium Hydride 1 Σ 1400 1360 0.971 1 1
C2 Carbon diatomic 1 Σg 1856 1827 0.984 2 2
SiH Silylidyne 1 Σ 2035 1971 0.968 3 3
CN Cyano radical 1 Σ 2125 2042 0.961 4 4
N2 Nitrogen diatomic 1 Σg 2355 2330 0.989 5 5
P2 Phosphorus diatomic 1 Σg 777 775 0.997 6 6
OH Hydroxyl radical 1 Σ 3738 3570 0.955 7 7
CO Carbon monoxide 1 Σ 2163 2143 0.991 8 8
NO Nitric oxide 1 Σ 2104 1876 0.892 9 9
O2 Oxygen diatomic 1 Σg 1590 1556 0.979 10 10
MgO magnesium oxide 1 Σ 809 775 0.957 11 11
SiO Silicon monoxide 1 Σ 1235 1230 0.995 12 12
SO Sulfur monoxide 1 Σ 1157 1138 0.984 13 13
S2 Sulfur diatomic 1 Σg 721 720 0.999 14 14
HF Hydrogen fluoride 1 Σ 4182 3961 0.947 15 15
BF Boron monofluoride 1 Σ 1411 1379 0.977 16 16
CF Fluoromethylidyne 1 Σ 1326 1286 0.970 17 17
NF nitrogen fluoride 1 Σ 1156 1123 0.971 18 18
F2 Fluorine diatomic 1 Σg 925 894 0.966 19 19
AlF Aluminum monofluoride 1 Σ 795 793 0.996 20 20
HCl Hydrogen chloride 1 Σ 3012 2886 0.958 21 21
ClO Monochlorine monoxide 1 Σ 843 843 0.999 22 22
ClF Chlorine monofluoride 1 Σ 778 773 0.994 23 23
Cl2 Chlorine diatomic 1 Σg 552 554 1.004 24 24
HCN Hydrogen cyanide 1 Σ 3440 3312 0.963 25 25
    2 Σ 2123 2089 0.984 25 26
    3 Π 723 712 0.984 25 27
H2O Water 1 A1 3841 3657 0.952 26 28
    2 A1 1668 1595 0.956 26 29
    3 B2 3943 3756 0.953 26 30
CO2 Carbon dioxide 1 Σg 1351 1333 0.986 27 31
    2 Σu 2399 2349 0.979 27 32
    3 Πu 667 667 1.000 27 33
N2O Nitrous oxide 1 Σ 2291 2224 0.971 28 34
    2 Σ 1305 1285 0.985 28 35
    3 Π 606 589 0.972 28 36
O3 Ozone 1 A1 1158 1110 0.959 29 37
    2 A1 720 705 0.980 29 38
    3 B2 1062 1042 0.982 29 39
H2S Hydrogen sulfide 1 A1 2732 2615 0.957 30 40
    2 A1 1211 1183 0.977 30 41
    3 B2 2749 2626 0.955 30 42
SO2 Sulfur dioxide 1 A1 1172 1151 0.982 31 43
    2 A1 520 518 0.996 31 44
    3 B2 1391 1362 0.979 31 45
CS2 Carbon disulfide 1 Σg 671 658 0.981 32 46
    2 Σu 1564 1535 0.981 32 47
    3 Πu 403 397 0.984 32 48
FNO Nitrosyl fluoride 1 A' 1856 1844 0.994 33 49
    2 A' 805 766 0.951 33 50
    3 A' 551 520 0.944 33 51
ClCN chlorocyanogen 1 Σ 2251 2216 0.984 34 52
    2 Σ 745 744 0.999 34 53
    3 Π 387 378 0.976 34 54
AlH3 aluminum trihydride 1 A1' 1945 1900 0.977 35 55
    2 A2" 717 698 0.973 35 56
    3 E' 1951 1883 0.965 35 57
    4 E' 796 783 0.984 35 58
C2H2 Acetylene 1 Σg 3506 3374 0.962 36 59
    2 Σg 2009 1974 0.983 36 60
    3 Σu 3415 3289 0.963 36 61
    4 Πg 587 612 1.042 36 62
    5 Πu 748 730 0.976 36 63
CCH2 vinylidene 1 A1 3134 3025 0.965 37 64
    2 A1 1670 1635 0.979 37 65
    3 A1 1227 1165 0.949 37 66
NH3 Ammonia 1 A1 3479 3337 0.959 38 67
    2 A1 1106 950 0.859 38 68
    3 E 3604 3444 0.956 38 69
    4 E 1689 1627 0.963 38 70
N2H2 (E)-diazene 1 Ag 3268 3058 0.936 39 71
    2 Ag 1623 1583 0.976 39 72
    3 Ag 1564 1529 0.978 39 73
    4 Au 1331 1289 0.968 39 74
    5 Bu 3301 3120 0.945 39 75
    6 Bu 1352 1316 0.974 39 76
PH3 Phosphine 1 A1 2423 2323 0.959 40 77
    2 A1 1024 992 0.969 40 78
    3 E 2433 2328 0.957 40 79
    4 E 1148 1118 0.974 40 80
H2CO Formaldehyde 1 A1 2932 2782 0.949 41 81
    2 A1 1786 1746 0.977 41 82
    3 A1 1545 1500 0.971 41 83
    4 B1 1194 1167 0.977 41 84
    5 B2 2999 2843 0.948 41 85
    6 B2 1277 1249 0.978 41 86
H2O2 Hydrogen peroxide 1 A 3809 3599 0.945 42 87
    2 A 1439 1402 0.974 42 88
    3 A 916 877 0.958 42 89
    4 A 364 371 1.019 42 90
    5 B 3808 3608 0.948 42 91
    6 B 1326 1266 0.954 42 92
H2CS Thioformaldehyde 1 A1 3090 2971 0.961 43 93
    2 A1 1503 1456 0.969 43 94
    3 A1 1073 1059 0.987 43 95
    4 B1 1010 990 0.980 43 96
    5 B2 3181 3025 0.951 43 97
    6 B2 1005 991 0.986 43 98
BCl3 Borane, trichloro- 1 A1' 479 471 0.984 44 99
    2 A2" 465 460 0.990 44 100
    3 E' 975 956 0.980 44 101
    4 E' 258 243 0.942 44 102
CH4 Methane 1 A1 3040 2917 0.959 45 103
    2 E 1572 1534 0.976 45 104
    3 T2 3161 3019 0.955 45 105
    4 T2 1345 1306 0.971 45 106
SiH4 Silane 1 A1 2261 2187 0.967 46 107
    2 E 993 975 0.982 46 108
    3 T2 2269 2191 0.966 46 109
    4 T2 937 914 0.975 46 110
C2H4 Ethylene 1 Ag 3161 3026 0.957 47 111
    2 Ag 1676 1623 0.968 47 112
    3 Ag 1372 1342 0.979 47 113
    4 Au 1050 1023 0.974 47 114
    5 B1u 3145 2989 0.950 47 115
    6 B1u 1480 1444 0.975 47 116
    7 B2g 947 940 0.992 47 117
    8 B2u 3253 3105 0.955 47 118
    9 B2u 823 826 1.003 47 119
    10 B3g 3227 3086 0.956 47 120
    11 B3g 1244 1217 0.979 47 121
    12 B3u 969 949 0.979 47 122

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 70 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 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