return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

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 CCSD(T)/6-31+G**
Calculated values were scaled by 0.9596.

Species Name mode Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 383 -229 1.598
F2CCCF2 tetrafluoroallene 11 E 90 69 -21 1.295
F2CCCF2 tetrafluoroallene 7 B2 581 366 -215 1.586
F2CCCF2 tetrafluoroallene 6 B2 1030 537 -493 1.917
F2CCCF2 tetrafluoroallene 5 B2 2052 687 -1365 2.987
H2CS- thioformaldehyde anion 4 B1 450 234 -216 1.921
HNCS Isothiocyanic acid 6 A" 539 426 -114 1.267
C6H6 Benzvalene 10 A1 996 746 -250 1.336
Li2O dilithium oxide 3 Πu 112 52 -59 2.142
CH3 Methyl radical 2 A2" 606 466 -140 1.301
CaS Calcium sulfide 1 Σ 462 364 -98 1.270
OClO- Chlorine dioxide anion 2 A1 418 313 -105 1.337
PO Phosphorus monoxide 1 Σ 1233 1720 486 0.717
C2H- Ethynyl anion 3 Π 505 402 -103 1.257
OPCl Phosphorus oxychloride 2 A' 308 479 171 0.644
OPCl Phosphorus oxychloride 3 A' 492 293 -199 1.678
H2OH2O water dimer 8 A' 103 161 58 0.638
H2OH2O water dimer 11 A" 108 159 51 0.680
H2OH2O water dimer 12 A" 88 135 47 0.653