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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/TZVP
Scale factor How many Source
Molecules Vibrations
0.953 ± 0.030 25 149 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2CO Formaldehyde 1 A1 2991 2782 0.930 1 1
    2 A1 1770 1746 0.986 1 2
    3 A1 1581 1500 0.949 1 3
    4 B1 1222 1167 0.955 1 4
    5 B2 3066 2843 0.927 1 5
    6 B2 1299 1249 0.962 1 6
CH4 Methane 1 A1 3086 2917 0.945 2 7
    2 E 1573 1534 0.975 2 8
    3 T2 3225 3019 0.936 2 9
    4 T2 1374 1306 0.950 2 10
C2H6 Ethane 1 A1g 3091 2896 0.937 3 11
    2 A1g 1457 1388 0.952 3 12
    3 A1g 1030 995 0.966 3 13
    4 A1u 331 289 0.872 3 14
    5 A2u 3091 2915 0.943 3 15
    6 A2u 1432 1370 0.957 3 16
    7 Eg 3166 2969 0.938 3 17
    8 Eg 1523 1468 0.964 3 18
    9 Eg 1247 1190 0.954 3 19
    10 Eu 3188 2974 0.933 3 20
    11 Eu 1525 1460 0.958 3 21
    12 Eu 837 822 0.982 3 22
C2H2 Acetylene 1 Σg 3557 3374 0.949 4 23
    2 Σg 1993 1974 0.991 4 24
    3 Σu 3468 3289 0.948 4 25
    4 Πg 349 612 1.752 4 26
    5 Πu 744 730 0.981 4 27
C3H6 Cyclopropane 1 A1' 3203 3038 0.948 5 28
    2 A1' 1549 1479 0.955 5 29
    3 A1' 1239 1188 0.959 5 30
    4 A1" 1195 1126 0.942 5 31
    5 A2' 1117 1070 0.958 5 32
    6 A2" 3307 3103 0.938 5 33
    7 A2" 882 854 0.968 5 34
    8 E' 3195 3025 0.947 5 35
    9 E' 1499 1438 0.959 5 36
    10 E' 1101 1029 0.935 5 37
    11 E' 908 866 0.953 5 38
    12 E" 3288 3082 0.937 5 39
    13 E" 1240 1188 0.958 5 40
    14 E" 772 739 0.958 5 41
CH3CHClCH3 Propane, 2-chloro- 1 A' 3196 3005 0.940 6 42
    2 A' 3178 2955 0.930 6 43
    3 A' 3145 2927 0.931 6 44
    4 A' 3086 2878 0.933 6 45
    5 A' 1524 1472 0.966 6 46
    6 A' 1518 1454 0.958 6 47
    7 A' 1452 1390 0.957 6 48
    8 A' 1335 1270 0.951 6 49
    9 A' 1218 1163 0.955 6 50
    10 A' 1109 1065 0.961 6 51
    11 A' 930 888 0.954 6 52
    12 A' 669 633 0.947 6 53
    13 A' 431 418 0.969 6 54
    14 A' 347 336 0.967 6 55
    15 A' 297 253 0.852 6 56
    16 A" 3192 2997 0.939 6 57
    17 A" 3172 2985 0.941 6 58
    18 A" 3083 2947 0.956 6 59
    19 A" 1503 1472 0.979 6 60
    20 A" 1502 1454 0.968 6 61
    21 A" 1434 1377 0.961 6 62
    22 A" 1377 1334 0.969 6 63
    23 A" 1179 1123 0.953 6 64
    24 A" 976 972 0.996 6 65
    25 A" 960 936 0.975 6 66
    26 A" 334 317 0.950 6 67
    27 A" 253 276 1.090 6 68
CH2CHCH3 Propene 1 A' 3288 3090 0.940 7 69
    2 A' 3200 3013 0.942 7 70
    3 A' 3189 2991 0.938 7 71
    4 A' 3173 2954 0.931 7 72
    5 A' 3077 2871 0.933 7 73
    6 A' 1715 1650 0.962 7 74
    7 A' 1522 1470 0.966 7 75
    8 A' 1477 1420 0.962 7 76
    9 A' 1433 1378 0.961 7 77
    10 A' 1339 1297 0.968 7 78
    11 A' 1207 1171 0.970 7 79
    12 A' 958 963 1.005 7 80
    13 A' 943 920 0.976 7 81
    14 A' 429 428 0.999 7 82
    15 A" 3154 2954 0.937 7 83
    16 A" 1491 1443 0.968 7 84
    17 A" 1079 1045 0.968 7 85
    18 A" 1016 991 0.976 7 86
    19 A" 846 912 1.079 7 87
    20 A" 564 578 1.025 7 88
    21 A" 198 174 0.880 7 89
CO2 Carbon dioxide 1 Σg 1343 1333 0.993 8 90
    2 Σu 2441 2349 0.962 8 91
    3 Πu 667 667 1.000 8 92
CO Carbon monoxide 1 Σ 2132 2170 1.018 9 93
BeO beryllium oxide 1 Σ 1369 1457 1.064 10 94
C3H5 Allyl radical 1 A1 3328 3114 0.936 11 95
    2 A1 3221 3048 0.946 11 96
    4 A1 1566 1488 0.950 11 97
    5 A1 1319 1245 0.944 11 98
    6 A1 1072 1066 0.995 11 99
    7 A1 440 427 0.971 11 100
    9 A2 559 549 0.982 11 101
    10 B1 1007 968 0.961 11 102
    11 B1 688 802 1.165 11 103
    12 B1 517 518 1.002 11 104
    13 B2 3326 3105 0.934 11 105
    14 B2 3213 3016 0.939 11 106
    15 B2 1527 1463 0.958 11 107
    16 B2 1440 1389 0.965 11 108
    17 B2 1145 1182 1.032 11 109
OH Hydroxyl radical 1 Σ 3806 3738 0.982 12 110
SO2 Sulfur dioxide 1 A1 1062 1151 1.085 13 111
    2 A1 479 518 1.082 13 112
    3 B2 1263 1362 1.078 13 113
LiH Lithium Hydride 1 Σ 1435 1405 0.980 14 114
BF3 Borane, trifluoro- 1 A1' 897 888 0.990 15 115
    2 A2" 702 691 0.984 15 116
    3 E' 1484 1449 0.977 15 117
    4 E' 477 480 1.007 15 118
HCl Hydrogen chloride 1 Σ 3067 2991 0.975 16 119
HF Hydrogen fluoride 1 Σ 4155 4138 0.996 17 120
NH3 Ammonia 1 A1 3531 3337 0.945 18 121
    2 A1 1074 950 0.885 18 122
    3 E 3684 3444 0.935 18 123
    4 E 1666 1627 0.977 18 124
H2SO4 Sulfuric acid 1 A 3793 3563 0.939 19 125
    2 A 1201 1216 1.013 19 126
    3 A 1151 1136 0.986 19 127
    4 A 798 831 1.042 19 128
    5 A 516 548 1.062 19 129
    6 A 424 422 0.993 19 130
    7 A 372 379 1.018 19 131
    8 A 252 224 0.888 19 132
    9 B 3789 3567 0.941 19 133
    10 B 1463 1452 0.993 19 134
    11 B 1162 1157 0.995 19 135
    12 B 848 882 1.040 19 136
    13 B 530 558 1.053 19 137
    14 B 480 506 1.054 19 138
    15 B 315 288 0.912 19 139
N2 Nitrogen diatomic 1 Σg 2196 2359 1.074 20 140
F2 Fluorine diatomic 1 Σg 980 917 0.936 21 141
AlF3 Aluminum trifluoride 1 A1' 678 690 1.018 22 142
    2 A2" 301 297 0.987 22 143
    3 E' 942 935 0.993 22 144
    4 E' 243 263 1.082 22 145
BeH2 beryllium dihydride 2 Σu 2324 2159 0.929 23 146
    3 Πu 767 698 0.910 23 147
Li2 Lithium diatomic 1 Σg 339 351 1.037 24 148
Na2 Sodium diatomic 1 Σg 149 159 1.068 25 149

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.

90
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