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 MP2=FULL/aug-cc-pVTZ
Calculated values were scaled by 0.9514.

Species Name mode Symmetry Experiment Theory difference ratio
HCN+ hydrogen cyanide cation 2 Σ 1800 2699 899 0.667
CH3CONH2 Acetamide 20 A 259 124 -135 2.094
HCN+ hydrogen cyanide cation 1 Σ 3050 3502 452 0.871
CHONH2 formamide 12 A" 289 169 -120 1.710
C3H6O 2-Propen-1-ol 24 A 188 110 -78 1.713
HCNO fulminic acid 5 Π 224 -288 -512 -0.779
NH2CN cyanamide 5 A' 408 593 185 0.687
CO+ carbon monoxide cation 1 Σ 2214 2741 526 0.808
C3H6O Oxetane 18 B1 90 -96 -186 -0.934
C6H6 Benzvalene 10 A1 996 736 -260 1.353
SiF2+ Silicon difluoride cation 2 A1 350 274 -76 1.279
CN Cyano radical 1 Σ 2069 2774 706 0.746
HCCN cyanomethylene 5 Π 129 -445 -574 -0.290
CH2OH Hydroxymethyl radical 9 A 234 409 175 0.573
CH3 Methyl radical 2 A2" 606 458 -148 1.323
C2H3+ vinyl cation 2 A1 2217 2903 686 0.764
O2+ diatomic oxygen cation 1 Σg 1906 1452 -454 1.313
O2 Oxygen diatomic 1 Σg 794 1226 432 0.648
C2H Ethynyl radical 2 Σ 1841 2416 576 0.762
C2H Ethynyl radical 3 Π 372 774 402 0.480
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.641
NO Nitric oxide 1 Σ 1904 3025 1120 0.630
C4H6 Methylenecyclopropane 17 B1 360 276 -84 1.304
FOOF Perfluoroperoxide 3 A 360 269 -91 1.338
FOOF Perfluoroperoxide 4 A 202 140 -62 1.441
C2Cl2+ dichloroacetylene cation 5 Πu 233 179 -54 1.299
VO Vanadium monoxide 1 Σ 1011 2000 989 0.506
SiP Silicon monophosphide 1 Σ 616 1054 438 0.584
O3 Ozone 3 B2 1042 2101 1059 0.496
NO2 Nitrogen dioxide 3 B2 1618 125749 124131 0.013
C3 carbon trimer 3 Πu 63 173 110 0.366
OPCl Phosphorus oxychloride 2 A' 308 484 176 0.637
OPCl Phosphorus oxychloride 3 A' 492 289 -203 1.705
C3O Tricarbon monoxide 5 Π 109 162 53 0.674
ONONO Nitrosyl nitrite 9 B2 380 47 -333 8.148
BrONO Bromine nitrite 4 A' 420 289 -131 1.454
ClONO chlorine nitrite 4 A' 406 278 -128 1.461
H2POH Phosphinous acid 9 A" 375 266 -109 1.411