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Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology |
You are here: Calculated > Vibrations > Bad Calculations > Bad vib. Calc. vs exp. OR Resources > Bad Calculations > Vibrations > Bad vib. Calc. vs exp. |
Calculated frequencies that differ from experiment by more than 400 cm-1 or have a ratio with experiment outside of 0.7 to 1.2 are listed
Calculated vibrational frequencies ("theory" in table) are calculated at
MP4/6-31G(2df,p)
Calculated values were scaled by 1.
Species | Name | mode | int rot | Symmetry | Experiment | Theory | difference | ratio |
---|---|---|---|---|---|---|---|---|
C2H2 | Acetylene | 4 | Πg | 612 | 480 | -132 | 1.275 | |
CH2NN | diazomethane | 6 | B1 | 406 | 272 | -134 | 1.493 | |
NH2CN | cyanamide | 5 | torsion | A' | 408 | 689 | 281 | 0.592 |
C2F2 | difluoroacetylene | 4 | Πg | 270 | 96 | -174 | 2.827 | |
CaO | Calcium monoxide | 1 | Σ | 723 | 1948 | 1225 | 0.371 | |
CaF2 | Calcium difluoride | 2 | A1 | 120 | 92 | -28 | 1.302 | |
NO | Nitric oxide | 1 | Σ | 1876 | 3481 | 1605 | 0.539 | |
N2O3 | Dinitrogen trioxide | 9 | torsion | A" | 63 | 172 | 109 | 0.366 |