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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/cc-pVQZ
Scale factor How many Source
Molecules Vibrations
0.962 ± 0.027 76 147 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2CO Formaldehyde 1 A1 2975 2782 0.935 1 1
    2 A1 1769 1746 0.987 1 2
    3 A1 1548 1500 0.969 1 3
    4 B1 1206 1167 0.968 1 4
    5 B2 3051 2843 0.932 1 5
    6 B2 1277 1249 0.978 1 6
CH4 Methane 1 A1 3077 2917 0.948 2 7
    2 E 1586 1534 0.968 2 8
    3 T2 3214 3019 0.939 2 9
    4 T2 1351 1306 0.967 2 10
C2H6 Ethane 1 A1g 3081 2896 0.940 3 11
    2 A1g 1431 1388 0.970 3 12
    3 A1g 1029 995 0.967 3 13
    4 A1u 313 289 0.924 3 14
    5 A2u 3084 2915 0.945 3 15
    6 A2u 1412 1370 0.970 3 16
    7 Eg 3157 2969 0.940 3 17
    8 Eg 1523 1468 0.964 3 18
    9 Eg 1230 1190 0.968 3 19
    10 Eu 3179 2974 0.936 3 20
    11 Eu 1522 1460 0.959 3 21
    12 Eu 827 822 0.994 3 22
C2H4 Ethylene 1 Ag 3197 3026 0.947 4 23
    2 Ag 1683 1623 0.964 4 24
    3 Ag 1383 1342 0.971 4 25
    4 Au 1076 1023 0.951 4 26
    5 B1u 3181 2989 0.940 4 27
    6 B1u 1482 1444 0.974 4 28
    7 B2g 964 940 0.975 4 29
    8 B2u 3296 3105 0.942 4 30
    9 B2u 828 826 0.998 4 31
    10 B3g 3271 3086 0.944 4 32
    11 B3g 1247 1217 0.976 4 33
    12 B3u 981 949 0.967 4 34
C2H2 Acetylene 1 Σg 3531 3374 0.956 5 35
    2 Σg 1978 1974 0.998 5 36
    3 Σu 3444 3289 0.955 5 37
    4 Πg 601 612 1.019 5 38
    5 Πu 752 730 0.971 5 39
CO2 Carbon dioxide 1 Σg 1335 1333 0.999 6 40
    2 Σu 2421 2349 0.970 6 41
    3 Πu 664 667 1.004 6 42
CO Carbon monoxide 1 Σ 2128 2170 1.019 7 43
BeO beryllium oxide 1 Σ 1415 1457 1.030 8 44
MgO magnesium oxide 1 Σ 1022 785 0.768 9 45
H2 Hydrogen diatomic 1 Σg 4519 4401 0.974 10 46
C3H5 Allyl radical 1 A1 3319 3114 0.938 11 47
    2 A1 3212 3048 0.949 11 48
    4 A1 1553 1488 0.958 11 49
    5 A1 1315 1245 0.947 11 50
    6 A1 1071 1066 0.996 11 51
    7 A1 434 427 0.984 11 52
    9 A2 599 549 0.916 11 53
    10 B1 1078 968 0.898 11 54
    11 B1 871 802 0.920 11 55
    12 B1 564 518 0.918 11 56
    13 B2 3317 3105 0.936 11 57
    14 B2 3203 3016 0.942 11 58
    15 B2 1514 1463 0.966 11 59
    16 B2 1427 1389 0.973 11 60
    17 B2 1133 1182 1.043 11 61
CS carbon monosulfide 1 Σ 1304 1285 0.985 12 62
CH Methylidyne 1 Σ 2952 2861 0.969 13 63
    1 Σ 3213 3145 0.979 13 64
OH Hydroxyl radical 1 Σ 3823 3738 0.978 14 65
CF Fluoromethylidyne 1 Σ 1331 1308 0.983 15 66
CCl carbon monochloride 1 Σ 904 877 0.970 16 67
SO2 Sulfur dioxide 1 A1 1123 1151 1.025 17 68
    2 A1 506 518 1.024 17 69
    3 B2 1340 1362 1.016 17 70
LiCl lithium chloride 1 Σ 635 643 1.012 18 71
LiH Lithium Hydride 1 Σ 1426 1405 0.986 19 72
BF3 Borane, trifluoro- 1 A1' 892 888 0.995 20 73
    2 A2" 695 691 0.994 20 74
    3 E' 1471 1449 0.985 20 75
    4 E' 480 480 1.000 20 76
HCl Hydrogen chloride 1 Σ 3050 2991 0.980 21 77
NaCl Sodium Chloride 1 Σ 352 365 1.036 22 78
HF Hydrogen fluoride 1 Σ 4159 4138 0.995 23 79
NH3 Ammonia 1 A1 3518 3337 0.949 24 80
    2 A1 1063 950 0.893 24 81
    3 E 3663 3444 0.940 24 82
    4 E 1677 1627 0.970 24 83
NaF sodium fluoride 1 Σ 531 536 1.008 25 84
N2 Nitrogen diatomic 1 Σg 2205 2359 1.070 26 85
H2O Water 1 A1 3853 3657 0.949 27 86
    2 A1 1643 1595 0.971 27 87
    3 B2 3975 3756 0.945 27 88
F2 Fluorine diatomic 1 Σg 1007 917 0.911 28 89
Cl2 Chlorine diatomic 1 Σg 583 560 0.961 29 90
H2S Hydrogen sulfide 1 A1 2780 2615 0.941 30 91
    2 A1 1214 1183 0.975 30 92
    3 B2 2799 2626 0.938 30 93
AlF3 Aluminum trifluoride 1 A1' 695 690 0.993 31 94
    2 A2" 297 297 1.000 31 95
    3 E' 960 935 0.974 31 96
    4 E' 247 263 1.065 31 97
BeH2 beryllium dihydride 2 Σu 2285 2159 0.945 32 98
    3 Πu 724 698 0.964 32 99
LiF lithium fluoride 1 Σ 898 911 1.014 33 100
ClF Chlorine monofluoride 1 Σ 808 783 0.969 34 101
SiO Silicon monoxide 1 Σ 1198 1242 1.037 35 102
SiF silicon monofluoride 1 Σ 853 857 1.005 36 103
MgS magnesium sulfide 1 Σ 562 529 0.941 37 104
C2 Carbon diatomic 1 Σg 1888 1855 0.983 38 105
LiO lithium oxide 1 Σ 809 815 1.007 39 106
P2 Phosphorus diatomic 1 Σg 737 781 1.059 40 107
P4 Phosphorus tetramer 1 A1 619 601 0.971 41 108
    2 E 370 361 0.974 41 109
    3 T2 468 467 0.997 41 110
BS boron sulfide 1 Σ 1217 1180 0.970 42 111
AlS Aluminum sulfide 1 Σ 707 617 0.873 43 112
CP Carbon monophosphide 1 Σ 1310 1240 0.946 44 113
NaO sodium monoxide 1 Σ 481 492 1.024 45 114
SiS silicon monosulfide 1 Σ 753 750 0.995 46 115
BO boron monoxide 1 Σ 1918 1885 0.983 47 116
Si2 Silicon diatomic 1 Σg 522 511 0.978 48 117
AlCl Aluminum monochloride 1 Σ 482 482 1.000 49 118
AlF Aluminum monofluoride 1 Σ 795 802 1.009 50 119
BeF Beryllium monofluoride 1 Σ 1253 1247 0.995 51 120
BeH beryllium monohydride 1 Σ 2115 2061 0.974 52 121
BeS beryllium sulfide 1 Σ 1001 998 0.997 53 122
BH Boron monohydride 1 Σ 2437 2367 0.971 54 123
NH Imidogen 1 Σ 3405 3283 0.964 55 124
    1 Σ 3426 3314 0.967 55 125
SiH Silylidyne 1 Σ 2104 2043 0.971 56 126
BeCl beryllium chloride 1 Σ 846 847 1.001 57 127
SO Sulfur monoxide 1 Σ 1148 1151 1.002 58 128
SH Mercapto radical 1 Σ 2770 2696 0.973 59 129
SiCl Clorosilylidyne 1 Σ 539 536 0.994 60 130
NF nitrogen fluoride 1 Σ 1181 1141 0.967 61 131
PH phosphorus monohydride 1 Σ 2438 2364 0.970 62 132
    1 Σ 2457 2415 0.983 62 133
AlH aluminum monohydride 1 Σ 1725 1682 0.975 63 134
MgH magnesium monohydride 1 Σ 1561 1493 0.956 64 135
Li2 Lithium diatomic 1 Σg 343 351 1.023 65 136
MgF Magnesium monofluoride 1 Σ 712 712 0.999 66 137
MgCl magnesium monochloride 1 Σ 464 462 0.997 67 138
ClO Monochlorine monoxide 1 Σ 851 854 1.003 68 139
SCl sulfur monochloride 1 Σ 595 575 0.966 69 140
PF phosphorus monofluoride 1 Σ 850 847 0.996 70 141
SF Monosulfur monofluoride 1 Σ 851 838 0.984 71 142
PCl phosphorus chloride 1 Σ 559 577 1.033 72 143
PN Phosphorus mononitride 1 Σ 1200 1337 1.114 73 144
BCl boron monochloride 1 Σ 857 840 0.980 74 145
S2 Sulfur diatomic 1 Σg 724 726 1.003 75 146
Na2 Sodium diatomic 1 Σg 156 159 1.017 76 147

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.

80
70
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