return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 HF/6-311+G(3df,2p)
Calculated values were scaled by 0.9086.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 174 61 0.649
CH3CONH2 Acetamide 20 A 259 143 -116 1.808
CH3COCH3 Acetone 12 A2 77 39 -38 1.987
CHONH2 formamide 12 A" 289 195 -94 1.481
CH3COCH2CH3 2-Butanone 33 A" 87 17 -70 5.047
CH3COOCH3 methyl acetate 27 A" 110 79 -31 1.400
C5H8 Cyclopentene 18 A' 254 144 -110 1.769
NH2CN cyanamide 5 A' 408 609 201 0.670
C2H3NO3 Oxamic acid 1 A' 3340 3741 401 0.893
C2H3NO3 Oxamic acid 3 A' 2600 3479 879 0.747
C2H3NO3 Oxamic acid 21 A" 162 49 -113 3.317
HCNO fulminic acid 5 Π 224 552 327 0.406
C5H8 1,4-Pentadiene 16 A 137 292 155 0.469
C2F2 difluoroacetylene 4 Πg 270 501 231 0.539
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 215 71 0.671
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 128 -43 1.333
C2H Ethynyl radical 3 Π 372 556 185 0.668
CH3 Methyl radical 2 A2" 606 374 -232 1.621
CH2OH Hydroxymethyl radical 8 A 482 689 207 0.700
CH2OH Hydroxymethyl radical 9 A 234 363 129 0.644
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 855 -281 1.329
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 133 -131 1.990
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 90 -268 3.965
C2Cl2 dichloroacetylene 4 Πg 333 488 155 0.682
CaF2 Calcium difluoride 2 A1 120 45 -75 2.660
PCl5 Phosphorus pentachloride 2 A1' 370 271 -99 1.366
N2O4 Dinitrogen tetroxide 3 Ag 265 417 152 0.636
N2O4 Dinitrogen tetroxide 4 Au 82 56 -26 1.461
N2O3 Dinitrogen trioxide 6 A' 241 390 149 0.618
N2O3 Dinitrogen trioxide 7 A' 205 327 122 0.626
N2O3 Dinitrogen trioxide 8 A" 414 636 222 0.651
N2O3 Dinitrogen trioxide 9 A" 63 115 52 0.550
NS Mononitrogen monosulfide 1 Σ 1219 860 -358 1.416
C4 Carbon tetramer 4 Πg 323 496 173 0.652
PS phosphorus sulfide 1 Σ 739 499 -240 1.482
AlO Aluminum monoxide 1 Σ 979 714 -265 1.371
ClOO chloroperoxy radical 2 A' 414 706 293 0.586
ClOO chloroperoxy radical 3 A' 201 439 237 0.459
Mg2 Magnesium diatomic 1 Σg 51 3 -48 19.144
Al2 Aluminum diatomic 1 Σg 286 458 172 0.624