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 CCD/cc-pVDZ
Calculated values were scaled by 0.9567.

Species Name mode Symmetry Experiment Theory difference ratio
C2H4+ Ethylene cation 4 Au 84 171 87 0.492
HCN+ hydrogen cyanide cation 2 Σ 1800 2717 917 0.662
HCN+ hydrogen cyanide cation 1 Σ 3050 3519 469 0.867
CH3OH Methyl alcohol 12 A" 200 331 131 0.604
CHONH2 formamide 12 A" 289 -259 -547 -1.116
C3F8 perfluoropropane 13 A2 276 217 -59 1.272
C10H8 naphthalene 27 B2g 770 594 -176 1.296
C3H6O 2-Propen-1-ol 24 A 188 107 -81 1.761
C5H8 Cyclopentene 18 A' 254 172 -82 1.479
NH2CN cyanamide 5 A' 408 730 322 0.559
CH2NN diazomethane 6 B1 406 290 -116 1.402
C3H6O Oxetane 18 B1 90 42 -47 2.121
C4H6O2 2,3-Butanedione 21 Bg 240 126 -114 1.910
HCNO fulminic acid 5 Π 224 -21 -246 -10.435
H2CS- thioformaldehyde anion 4 B1 450 -162 -612 -2.784
CH3SSCH3 Disulfide, dimethyl 13 A 117 92 -25 1.266
SiF2+ Silicon difluoride cation 2 A1 350 273 -77 1.282
C6H6 Benzvalene 10 A1 996 740 -256 1.347
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.681
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 338 -118 1.350
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 117 -54 1.466
CN Cyano radical 1 Σ 2069 2529 460 0.818
C2H Ethynyl radical 3 Π 372 728 357 0.510
CH3 Methyl radical 2 A2" 606 382 -225 1.588
CH2OH Hydroxymethyl radical 9 A 234 427 193 0.548
HCCN cyanomethylene 5 Π 129 -407 -535 -0.317
CHCl2 dichloromethyl radical 4 A' 190 294 104 0.646
FOOF Perfluoroperoxide 1 A 1210 952 -258 1.271
O3 Ozone 3 B2 1042 1650 608 0.632
OClO- Chlorine dioxide anion 2 A1 418 333 -85 1.257
NO Nitric oxide 1 Σ 1904 2917 1013 0.653
NO2 Nitrogen dioxide 1 A1 1318 3201 1883 0.412
NO2 Nitrogen dioxide 2 A1 750 -936 -1686 -0.802
NO2 Nitrogen dioxide 3 B2 1618 8595 6977 0.188
N2O3 Dinitrogen trioxide 9 A" 63 146 83 0.432
VO Vanadium monoxide 1 Σ 1011 1886 874 0.536
C3 carbon trimer 3 Πu 63 128 65 0.496
SiP Silicon monophosphide 1 Σ 616 917 302 0.671
PO Phosphorus monoxide 1 Σ 1233 2150 916 0.574
PN+ phosphorus nitride cation 1 Σ 1200 1966 766 0.610
Cl3- trichloride anion 2 Σu 327 242 -85 1.349
OPCl Phosphorus oxychloride 2 A' 308 482 174 0.639
OPCl Phosphorus oxychloride 3 A' 492 297 -195 1.657
Mg2 Magnesium diatomic 1 Σg 51 14 -37 3.594
H2POH Phosphinous acid 9 A" 375 233 -142 1.611