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Compare vibrational frequencies in CCCBDB for C2H4O4 (Formic acid dimer)

HF/3-21G

18 11 26 13 55
Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency Scaled
Frequency
Harm.
diff
Fund.
diff
Symmetry Harmonic
Frequency
Fundamental
Frequency
Comment
1 Ag 3341 3025           
2 Ag 3217 2913   -36 Ag   2949 C-H was 2
3 Ag 1821 1649   -21 Ag   1670 C=O was 3
4 Ag 1595 1444   29 Ag   1415 C-O-H was 4
5 Ag 1548 1402   27 Ag   1375 H-C-O was 5
6 Ag 1333 1207   -7 Ag   1214 C-O was 6
7 Ag 732 663   -14 Ag   677 O-C=O was 7
8 Ag 249 226           
9 Ag 184 166   29 Ag   137 ipb O-H.O was 9
10 Au 1231 1115   65 Au   1050 opb C-H was 13
11 Au 1120 1014   92 Au   922 opb O-H was 14
12 Au 206 186   18 Au   168 opb O-H.O was 15
13 Au 96 87   17 Au   69 twist was 16
14 Bg 1218 1103   43 Bg   1060 opb C-H was 10
15 Bg 1079 977           
16 Bg 293 265   35 Bg   230 opb O-H.O was 12
17 Bu 3368 3050   -34 Bu   3084 O-H was 17
18 Bu 3309 2996   58 Bu   2939 C-H was 18
19 Bu 1880 1703   -43 Bu   1746 C=O was 19
20 Bu 1569 1421   -33 Bu   1454 C-O-H was 20
21 Bu 1543 1398   34 Bu   1364 H-C-O was 21
22 Bu 1324 1199   -19 Bu   1218 C-O was 22
23 Bu 760 688   -10 Bu   698 O-C=O was 23
24 Bu 328 297   29 Bu   268 O-H.O was 24
The calculated vibrational frequencies were scaled by 0.9056

See section Calculated; Vibrations; Scale Factors; Set scaling factors to change the scale factors used here.
See section Calculated; Vibrations; Scale Factors; Calculate a scale factor to determine the least squares best scaling factor.
See section Calculated; Vibrations; Scale Factors; Scale factor uncertainty for information on where the above scaling factor is from.