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 mPW1PW91/cc-pVDZ
Calculated values were scaled by 0.9583.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 176 63 0.643
CH3COOH Acetic acid 18 A" 93 74 -19 1.263
CH3OH Methyl alcohol 12 A" 200 321 121 0.623
CH3COCH3 Acetone 12 A2 77 31 -46 2.467
C2H6O2S Dimethyl sulfone 20 B1 262 199 -63 1.315
C2H4+ Ethylene cation 4 Au 84 -441 -525 -0.191
CHONH2 formamide 12 A" 289 92 -197 3.147
C2F6 hexafluoroethane 4 A1u 68 47 -21 1.449
C3F8 perfluoropropane 13 A2 276 208 -68 1.324
CH3COOCH3 methyl acetate 27 A" 110 47 -63 2.321
C3H6O 2-Propen-1-ol 24 A 188 111 -77 1.698
C4H8S Thiophene, tetrahydro- 5 A 1464 2952 1488 0.496
C4H8S Thiophene, tetrahydro- 6 A 1441 2952 1511 0.488
C4H8S Thiophene, tetrahydro- 7 A 1321 2940 1619 0.449
C4H8S Thiophene, tetrahydro- 8 A 1276 2939 1663 0.434
C4H8S Thiophene, tetrahydro- 12 A 888 1394 506 0.637
C4H8S Thiophene, tetrahydro- 13 A 829 1306 477 0.635
C4H8S Thiophene, tetrahydro- 14 A 822 1277 455 0.644
C4H8S Thiophene, tetrahydro- 15 A 678 1245 567 0.545
C4H8S Thiophene, tetrahydro- 16 A 472 1224 752 0.386
C4H8S Thiophene, tetrahydro- 17 A 290 1186 896 0.245
C5H8 Cyclopentene 18 A' 254 151 -103 1.680
NH2CN cyanamide 5 A' 408 620 212 0.658
C4H6O2 2,3-Butanedione 21 Bg 240 98 -142 2.458
C5H12 Propane, 2,2-dimethyl- 12 T1 203 296 93 0.686
C2H3NO3 Oxamic acid 3 A' 2600 3459 859 0.752
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.281
C2H3NO3 Oxamic acid 21 A" 162 72 -90 2.257
C3H6O Oxetane 18 B1 90 56 -34 1.598
HCNO fulminic acid 5 Π 224 161 -63 1.389
C5H8 1,4-Pentadiene 16 A 137 285 148 0.481
C6H6 Benzvalene 10 A1 996 738 -258 1.350
H2CS- thioformaldehyde anion 4 B1 450 -95 -545 -4.754
SiF2+ Silicon difluoride cation 2 A1 350 256 -94 1.369
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 347 -109 1.315
CH3OO methylperoxy radical 12 A" 170 132 -38 1.284
CH3 Methyl radical 2 A2" 606 440 -166 1.378
CH2OH Hydroxymethyl radical 9 A 234 421 187 0.556
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 866 -270 1.311
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 152 -112 1.737
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 100 -258 3.578
HCCN cyanomethylene 5 Π 129 -256 -385 -0.503
CHCl2 dichloromethyl radical 4 A' 190 294 104 0.647
C4H6 Methylenecyclopropane 17 B1 360 284 -76 1.267
HClO4 perchloric acid 12 A" 191 147 -44 1.303
OClO- Chlorine dioxide anion 2 A1 418 326 -92 1.284
N2O3 Dinitrogen trioxide 9 A" 63 147 84 0.427
C3O Tricarbon monoxide 5 Π 109 159 50 0.687
C3 carbon trimer 3 Πu 63 117 54 0.541
TiO2 Titanium dioxide 1 A1 959 334 -625 2.873
SiH- silicon monohydride anion 1 Σ 2175 1730 -445 1.257
ClOO chloroperoxy radical 2 A' 414 287 -127 1.443
ClOO chloroperoxy radical 3 A' 201 131 -70 1.532
OPCl Phosphorus oxychloride 2 A' 308 480 172 0.641
OPCl Phosphorus oxychloride 3 A' 492 290 -202 1.695
H2POH Phosphinous acid 9 A" 375 234 -142 1.605
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.596