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

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at AM1
Scale factor How many Source
Molecules Vibrations
0.954 ± 0.059 231 2457 cccbdb
Jump to histogram
Formula Name Mode Symmetry Frequency Count
Theory Experiment ratio molecules vibrations
H2CO Formaldehyde 1 A1 3120 2782 0.892 1 1
    2 A1 2053 1746 0.850 1 2
    3 A1 1443 1500 1.039 1 3
    4 B1 1155 1167 1.011 1 4
    5 B2 3086 2843 0.921 1 5
    6 B2 1162 1249 1.074 1 6
CH3OH Methyl alcohol 1 A' 3502 3681 1.051 2 7
    2 A' 3148 3000 0.953 2 8
    3 A' 3074 2844 0.925 2 9
    4 A' 1520 1477 0.971 2 10
    5 A' 1471 1455 0.989 2 11
    6 A' 1381 1345 0.974 2 12
    7 A' 1361 1060 0.779 2 13
    8 A' 1128 1033 0.916 2 14
    9 A" 3055 2960 0.969 2 15
    10 A" 1369 1477 1.079 2 16
    11 A" 1185 1165 0.983 2 17
    12 A" 290 200 0.690 2 18
C2H6 Ethane 1 A1g 3147 2896 0.920 3 19
    2 A1g 1445 1388 0.961 3 20
    3 A1g 1247 995 0.798 3 21
    4 A1u 202 289 1.429 3 22
    5 A2u 3164 2915 0.921 3 23
    6 A2u 1431 1370 0.957 3 24
    7 Eg 3048 2969 0.974 3 25
    8 Eg 1394 1468 1.053 3 26
    9 Eg 1183 1190 1.006 3 27
    10 Eu 3072 2974 0.968 3 28
    11 Eu 1395 1460 1.047 3 29
    12 Eu 889 822 0.924 3 30
HCN Hydrogen cyanide 1 Σ 3386 3312 0.978 4 31
    2 Σ 2380 2089 0.878 4 32
    3 Π 924 712 0.771 4 33
CH3CHClCH3 Propane, 2-chloro- 1 A' 3155 3005 0.952 5 34
    2 A' 3069 2955 0.963 5 35
    3 A' 3061 2927 0.956 5 36
    4 A' 3028 2878 0.950 5 37
    5 A' 1439 1472 1.023 5 38
    6 A' 1393 1454 1.044 5 39
    7 A' 1386 1390 1.003 5 40
    8 A' 1255 1270 1.012 5 41
    9 A' 1210 1163 0.961 5 42
    10 A' 1085 1065 0.982 5 43
    11 A' 1035 888 0.858 5 44
    12 A' 713 633 0.888 5 45
    13 A' 461 418 0.907 5 46
    14 A' 357 336 0.941 5 47
    15 A' 174 253 1.451 5 48
    16 A" 3156 2997 0.950 5 49
    17 A" 3064 2985 0.974 5 50
    18 A" 3059 2947 0.963 5 51
    19 A" 1426 1472 1.032 5 52
    20 A" 1389 1454 1.047 5 53
    21 A" 1385 1377 0.994 5 54
    22 A" 1379 1334 0.967 5 55
    23 A" 1216 1123 0.924 5 56
    24 A" 1014 972 0.958 5 57
    25 A" 984 936 0.951 5 58
    26 A" 334 317 0.949 5 59
    27 A" 151 276 1.828 5 60
C5H11N Piperidine 1 A' 3408 3341 0.980 6 61
    2 A' 3104 2947 0.949 6 62
    3 A' 3096 2931 0.947 6 63
    4 A' 3043 2917 0.959 6 64
    5 A' 3037 2892 0.952 6 65
    6 A' 3019 2850 0.944 6 66
    7 A' 2949 2730 0.926 6 67
    8 A' 1483 1476 0.995 6 68
    9 A' 1419 1452 1.023 6 69
    10 A' 1411 1444 1.023 6 70
    11 A' 1403 1386 0.988 6 71
    12 A' 1387 1365 0.984 6 72
    13 A' 1253 1346 1.074 6 73
    14 A' 1239 1266 1.022 6 74
    15 A' 1185 1164 0.983 6 75
    16 A' 1179 1035 0.878 6 76
    17 A' 1078 1006 0.933 6 77
    18 A' 1038 906 0.873 6 78
    19 A' 1019 853 0.837 6 79
    20 A' 917 822 0.896 6 80
    21 A' 828 743 0.898 6 81
    22 A' 608 546 0.898 6 82
    23 A' 493 432 0.877 6 83
    24 A' 307 404 1.315 6 84
    25 A' 197 246 1.248 6 85
    26 A" 3102 2940 0.948 6 86
    27 A" 3039 2902 0.955 6 87
    28 A" 3033 2850 0.940 6 88
    29 A" 2948 2803 0.951 6 89
    30 A" 1546 1468 0.950 6 90
    31 A" 1462 1460 0.999 6 91
    32 A" 1417 1436 1.013 6 92
    33 A" 1401 1332 0.951 6 93
    34 A" 1385 1318 0.951 6 94
    35 A" 1376 1285 0.934 6 95
    36 A" 1320 1258 0.953 6 96
    37 A" 1246 1191 0.956 6 97
    38 A" 1218 1146 0.941 6 98
    39 A" 1141 1115 0.977 6 99
    40 A" 1140 1052 0.923 6 100
    41 A" 1037 964 0.930 6 101
    42 A" 989 874 0.884 6 102
    43 A" 847 810 0.956 6 103
    44 A" 500 445 0.890 6 104
    45 A" 194 254 1.312 6 105
C5H6 1,3-Cyclopentadiene 1 A1 3275 3091 0.944 7 106
    2 A1 3258 3075 0.944 7 107
    3 A1 3116 2886 0.926 7 108
    4 A1 1704 1500 0.880 7 109
    5 A1 1425 1378 0.967 7 110
    6 A1 1380 1365 0.989 7 111
    7 A1 1273 1106 0.869 7 112
    8 A1 1132 994 0.878 7 113
    9 A1 1063 915 0.861 7 114
    10 A1 841 802 0.954 7 115
    11 A2 1079 1100 1.020 7 116
    12 A2 969 941 0.971 7 117
    13 A2 827 700 0.847 7 118
    14 A2 487 516 1.059 7 119
    15 B1 3047 2900 0.952 7 120
    16 B1 1010 925 0.916 7 121
    17 B1 902 891 0.988 7 122
    18 B1 739 664 0.899 7 123
    19 B1 343 350 1.020 7 124
    20 B2 3266 3105 0.951 7 125
    21 B2 3257 3043 0.934 7 126
    22 B2 1759 1580 0.898 7 127
    23 B2 1349 1292 0.958 7 128
    24 B2 1281 1239 0.968 7 129
    25 B2 1135 1090 0.960 7 130
    26 B2 1101 959 0.871 7 131
    27 B2 866 805 0.929 7 132
CF2 Difluoromethylene 1 A1 1435 1225 0.854 8 133
    2 A1 559 667 1.193 8 134
    3 B2 1487 1114 0.749 8 135
CH Methylidyne 1 Σ 3322 3145 0.947 9 136
OH Hydroxyl radical 1 Σ 3615 3738 1.034 10 137
N2 Nitrogen diatomic 1 Σg 2744 2359 0.860 11 138
Cl2 Chlorine diatomic 1 Σg 794 560 0.705 12 139
AlF3 Aluminum trifluoride 1 A1' 868 690 0.795 13 140
    2 A2" 245 297 1.212 13 141
    3 E' 1201 935 0.779 13 142
    4 E' 213 263 1.233 13 143
FNO Nitrosyl fluoride 1 A' 2185 1844 0.844 14 144
    2 A' 1207 766 0.635 14 145
    3 A' 726 520 0.717 14 146
P2 Phosphorus diatomic 1 Σg 936 781 0.834 15 147
AlCl Aluminum monochloride 1 Σ 718 482 0.671 16 148
BeH beryllium monohydride 1 Σ 1981 2061 1.040 17 149
NH Imidogen 1 Σ 3497 3314 0.948 18 150
SiH2 silicon dihydride 1 A1 2250 1996 0.887 19 151
    2 A1 845 999 1.182 19 152
    3 B2 2222 1993 0.897 19 153
PH phosphorus monohydride 1 Σ 2476 2415 0.976 20 154
ClO Monochlorine monoxide 1 Σ 907 854 0.941 21 155
SCl sulfur monochloride 1 Σ 768 575 0.749 22 156

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