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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at QCISD/cc-pVTZ
Scale factor How many Source
Molecules Vibrations
0.956 ± 0.023 62 258 cccbdb
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Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
C2H2 Acetylene 1 Σg 3533 3374 0.955 1 1
    2 Σg 2040 1974 0.968 1 2
    3 Σu 3429 3289 0.959 1 3
    4 Πg 617 612 0.991 1 4
    5 Πu 766 730 0.954 1 5
HCN Hydrogen cyanide 3 Π 741 712 0.960 2 6
    2 Σ 2162 2089 0.966 2 7
    1 Σ 3467 3312 0.955 2 8
CH3NH2 methyl amine 15 A" 307 268 0.872 3 9
    14 A" 985     3 10
    13 A" 1371 1335 0.974 3 11
    12 A" 1540 1485 0.964 3 12
    11 A" 3129 2985 0.954 3 13
    10 A" 3609 3427 0.950 3 14
    9 A' 883 780 0.884 3 15
    8 A' 1081 1044 0.966 3 16
    7 A' 1198 1130 0.943 3 17
    6 A' 1474 1430 0.970 3 18
    5 A' 1521 1473 0.968 3 19
    4 A' 1684 1623 0.964 3 20
    3 A' 3013 2820 0.936 3 21
    2 A' 3094 2961 0.957 3 22
    1 A' 3530 3361 0.952 3 23
CH3Cl Methyl chloride 6 E 1043 1015 0.973 4 24
    5 E 1506 1455 0.966 4 25
    4 E 3197 3042 0.952 4 26
    3 A1 755 732 0.970 4 27
    2 A1 1401 1355 0.967 4 28
    1 A1 3097 2966 0.958 4 29
C2H4 Ethylene 12 B3u 986 949 0.963 5 30
    11 B3g 1255 1217 0.970 5 31
    10 B3g 3236 3086 0.954 5 32
    9 B2u 832 826 0.992 5 33
    8 B2u 3262 3105 0.952 5 34
    7 B2g 969 940 0.969 5 35
    6 B1u 1493 1444 0.967 5 36
    5 B1u 3156 2989 0.947 5 37
    4 Au 1063 1023 0.962 5 38
    3 Ag 1386 1342 0.968 5 39
    2 Ag 1700 1623 0.955 5 40
    1 Ag 3176 3026 0.953 5 41
CH4 Methane 4 T2 1356 1306 0.963 6 42
    3 T2 3164 3019 0.954 6 43
    2 E 1581 1534 0.971 6 44
    1 A1 3047 2917 0.957 6 45
HCOOH Formic acid 9 A" 676 638 0.944 7 46
    8 A" 1081 1033 0.956 7 47
    7 A' 639 625 0.978 7 48
    6 A' 1156 1105 0.956 7 49
    5 A' 1341 1229 0.917 7 50
    4 A' 1431 1387 0.969 7 51
    3 A' 1851 1770 0.956 7 52
    2 A' 3113 2943 0.945 7 53
    1 A' 3808 3570 0.938 7 54
CCl4 Carbon tetrachloride 4 T2 321 314 0.979 8 55
    3 T2 825 776 0.940 8 56
    2 E 222 217 0.979 8 57
    1 A1 470 459 0.976 8 58
CCl2O Phosgene 2 A1 584 567 0.971 9 59
    1 A1 1883 1827 0.970 9 60
C3H6 Cyclopropane 14 E" 750 739 0.986 10 61
    13 E" 1231 1188 0.965 10 62
    12 E" 3244 3082 0.950 10 63
    11 E' 906 866 0.956 10 64
    10 E' 1078 1029 0.954 10 65
    9 E' 1493 1438 0.963 10 66
    8 E' 3163 3025 0.956 10 67
    7 A2" 865 854 0.987 10 68
    6 A2" 3264 3103 0.951 10 69
    5 A2' 1109 1070 0.965 10 70
    4 A1" 1174 1126 0.959 10 71
    3 A1' 1230 1188 0.966 10 72
    2 A1' 1547 1479 0.956 10 73
    1 A1' 3175 3038 0.957 10 74
MgO magnesium oxide 1 Σ 719 785 1.092 11 75
CS2 Carbon disulfide 3 Πu 410 397 0.969 12 76
    2 Σu 1552 1535 0.989 12 77
    1 Σg 676 658 0.974 12 78
HNCO Isocyanic acid 6 A" 641 656 1.024 13 79
    5 A' 569 577 1.014 13 80
    4 A' 832 777 0.933 13 81
    3 A' 1329 1327 0.999 13 82
CN Cyano radical 1 Σ 2177 2069 0.950 14 83
HNCO Isocyanic acid 2 A' 2328 2269 0.975 15 84
    1 A' 3721 3538 0.951 15 85
CCl2O Phosgene 3 A1 306 285 0.932 16 86
    4 B1 598 580 0.969 16 87
    5 B2 883 849 0.962 16 88
    6 B2 453 440 0.970 16 89
CF2Cl2 difluorodichloromethane 1 A1 1162 1101 0.947 17 90
    2 A1 684 667 0.975 17 91
    3 A1 468 458 0.979 17 92
CS carbon monosulfide 1 Σ 1288 1285 0.998 18 93
CF2Cl2 difluorodichloromethane 4 A1 266 262 0.985 19 94
    5 A2 328 322 0.980 19 95
    6 B1 944 902 0.955 19 96
CH Methylidyne 1 Σ 2852 2861 1.003 20 97
CF2Cl2 difluorodichloromethane 7 B1 447 437 0.978 21 98
    8 B2 1234 1159 0.939 21 99
    9 B2 444 446 1.003 21 100
CH2CHCH3 Propene 1 A' 3248 3090 0.951 22 101
    2 A' 3171 3013 0.950 22 102
    3 A' 3157 2991 0.947 22 103
    4 A' 3129 2954 0.944 22 104
    5 A' 3047 2871 0.942 22 105
    6 A' 1728 1650 0.955 22 106
    7 A' 1515 1470 0.970 22 107
    8 A' 1472 1420 0.965 22 108
    9 A' 1425 1378 0.967 22 109
    10 A' 1337 1297 0.970 22 110
    11 A' 1205 1171 0.972 22 111
    12 A' 953 963 1.010 22 112
    13 A' 940 920 0.979 22 113
    14 A' 424 428 1.011 22 114
    15 A" 3105 2954 0.951 22 115
    16 A" 1502 1443 0.961 22 116
    17 A" 1084 1045 0.964 22 117
    18 A" 1032 991 0.960 22 118
    19 A" 950 912 0.960 22 119
    20 A" 594 578 0.974 22 120
    21 A" 202 174 0.863 22 121
CH2CCH2 allene 11 E 361 355 0.985 23 122
OCS Carbonyl sulfide 1 Σ 2117 2062 0.974 24 123
    2 Σ 870 859 0.988 24 124
    3 Π 534 520 0.975 24 125
ClCN chlorocyanogen 1 Σ 2304 2216 0.962 25 126
NaCl Sodium Chloride 1 Σ 354 365 1.031 26 127
ClCN chlorocyanogen 2 Σ 747 744 0.996 27 128
NH3 Ammonia 1 A1 3499 3337 0.954 28 129
    2 A1 1110 950 0.856 28 130
    3 E 3623 3444 0.951 28 131
    4 E 1700 1627 0.957 28 132
NaF sodium fluoride 1 Σ 550 536 0.975 29 133
ClCN chlorocyanogen 3 Π 395 378 0.956 30 134
CO Carbon monoxide 1 Σ 2187 2170 0.992 31 135
H2CS Thioformaldehyde 1 A1 3107 2971 0.956 32 136
    2 A1 1517 1456 0.959 32 137
    3 A1 1089 1059 0.973 32 138
    4 B1 1030 990 0.961 32 139
    5 B2 3196 3025 0.946 32 140
    6 B2 1014 991 0.977 32 141
BeO beryllium oxide 1 Σ 1434 1457 1.016 33 142
LiOH lithium hydroxide 1 Σ 4050 3688 0.910 34 143
    2 Σ 959 871 0.907 34 144
    3 Π 323 257 0.793 34 145
NaOH sodium hydroxide 1 Σ 3995 3637 0.910 35 146
    2 Σ 572 540 0.945 35 147
    3 Π 227 300 1.319 35 148
H2 Hydrogen diatomic 1 Σg 4409 4401 0.998 36 149
CF2 Difluoromethylene 1 A1 1271 1225 0.964 37 150
    2 A1 682 667 0.978 37 151
    3 B2 1181 1114 0.944 37 152
HCO Formyl radical 1 A' 2725 2434 0.893 38 153
    2 A' 1911 1868 0.978 38 154
    3 A' 1141 1081 0.947 38 155
ClNO Nitrosyl chloride 1 A' 1845 1800 0.975 39 156
    2 A' 630 596 0.946 39 157
    3 A' 356 332 0.932 39 158
HO2 Hydroperoxy radical 1 A' 3719 3436 0.924 40 159
    2 A' 1451 1392 0.959 40 160
    3 A' 1130 1098 0.971 40 161
CH Methylidyne 1 Σ 3134 3145 1.004 41 162
OH Hydroxyl radical 1 Σ 3772 3738 0.991 42 163
CCl carbon monochloride 1 Σ 869 877 1.009 43 164
HNC hydrogen isocyanide 1 Σ 3857 3653 0.947 44 165
    2 Σ 2087 2029 0.972 44 166
    3 Π 484 477 0.985 44 167
SO2 Sulfur dioxide 1 A1 1195 1151 0.963 45 168
    2 A1 530 518 0.978 45 169
    3 B2 1394 1362 0.977 45 170
SO3 Sulfur trioxide 1 A1' 1096 1065 0.972 46 171
    2 A2" 506 498 0.984 46 172
    3 E' 1428 1391 0.974 46 173
    4 E' 532 530 0.995 46 174
CO2 Carbon dioxide 1 Σg 1372 1333 0.971 47 175
    2 Σu 2414 2349 0.973 47 176
    3 Πu 678 667 0.984 47 177
CF2O Carbonic difluoride 1 A1 2007 1928 0.961 48 178
    2 A1 1000 965 0.965 48 179
    3 A1 596 584 0.980 48 180
CH3OH Methyl alcohol 12 A" 306 200 0.653 49 181
    11 A" 1193 1165 0.977 49 182
    10 A" 1520 1477 0.971 49 183
    9 A" 3080 2960 0.961 49 184
    8 A' 1080 1033 0.956 49 185
    7 A' 1109 1060 0.956 49 186
    6 A' 1405 1345 0.958 49 187
    5 A' 1503 1455 0.968 49 188
    4 A' 1536 1477 0.962 49 189
    3 A' 3027 2844 0.940 49 190
    2 A' 3142 3000 0.955 49 191
    1 A' 3901 3681 0.944 49 192
CF2O Carbonic difluoride 4 B1 801 774 0.966 50 193
    5 B2 1318 1249 0.948 50 194
    6 B2 635 626 0.985 50 195
CH2CCH2 allene 1 A1 3166 3015 0.952 51 196
    2 A1 1507 1443 0.958 51 197
    3 A1 1100 1073 0.975 51 198
    4 B1 884 865 0.978 51 199
    5 B2 3165 3007 0.950 51 200
    6 B2 2050 1957 0.954 51 201
    7 B2 1453 1398 0.962 51 202
    8 E 3247 3086 0.950 51 203
    9 E 1031 999 0.969 51 204
    10 E 882 841 0.954 51 205
H2CO Formaldehyde 6 B2 1287 1249 0.971 52 206
    5 B2 3018 2843 0.942 52 207
    4 B1 1213 1167 0.962 52 208
    3 A1 1557 1500 0.963 52 209
    2 A1 1817 1746 0.961 52 210
    1 A1 2953 2782 0.942 52 211
BF3 Borane, trifluoro- 3 E' 1503 1449 0.964 53 212
    4 E' 487 480 0.986 53 213
NaH sodium hydride 1 Σ 1132 1172 1.036 54 214
HCl Hydrogen chloride 1 Σ 3019 2991 0.991 55 215
HF Hydrogen fluoride 1 Σ 4202 4138 0.985 56 216
MgH2 magnesium dihydride 2 Σu 1636 1572 0.961 57 217
    3 Πu 441 440 0.998 57 218
H2O2 Hydrogen peroxide 1 A 3846 3599 0.936 58 219
    2 A 1465 1402 0.957 58 220
    3 A 968 877 0.906 58 221
    4 A 383 371 0.968 58 222
    5 B 3845 3608 0.938 58 223
    6 B 1354 1266 0.935 58 224
N2 Nitrogen diatomic 1 Σg 2409 2359 0.979 59 225
H2O Water 1 A1 3873 3657 0.944 60 226
    2 A1 1677 1595 0.951 60 227
    3 B2 3976 3756 0.945 60 228
F2 Fluorine diatomic 1 Σg 1009 917 0.909 61 229
Cl2 Chlorine diatomic 1 Σg 562 560 0.996 62 230
HNO2 Nitrous acid 1 A' 3834 3591 0.937 63 231
    2 A' 1782 1700 0.954 63 232
    3 A' 1348 1263 0.937 63 233
    4 A' 877 790 0.901 63 234
    5 A' 662 596 0.899 63 235
    6 A" 573 543 0.948 63 236
H2S Hydrogen sulfide 1 A1 2734 2615 0.957 64 237
    2 A1 1219 1183 0.970 64 238
    3 B2 2748 2626 0.956 64 239
F2O Difluorine monoxide 1 A1 1008 928 0.920 65 240
    2 A1 494 461 0.933 65 241
    3 B2 952 831 0.873 65 242
NF3 Nitrogen trifluoride 1 A1 1089 1032 0.948 66 243
    2 A1 681 647 0.951 66 244
    3 E 1003 907 0.905 66 245
    4 E 519 492 0.949 66 246
CF Fluoromethylidyne 1 Σ 1328 1308 0.985 67 247
LiCl lithium chloride 1 Σ 639 643 1.006 68 248
LiH Lithium Hydride 1 Σ 1395 1405 1.008 69 249
SiO2 silicon dioxide 2 Σu 1449 1416 0.977 70 250
    3 Πu 300 273 0.907 70 251
BF3 Borane, trifluoro- 1 A1' 905 888 0.981 71 252
    2 A2" 704 691 0.981 71 253
C2Cl2 dichloroacetylene 1 Σg 2341 2234 0.954 72 254
    2 Σg 478 477 0.998 72 255
    3 Σu 1004 988 0.984 72 256
    4 Πg 369 333 0.904 72 257
    5 Πu 180 172 0.955 72 258

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.

180
160
140
120
100
80
60
40
20
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