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 B2PLYP/6-31G*
Calculated values were scaled by 0.9492.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 171 58 0.661
CH3OH Methyl alcohol 12 A" 200 333 133 0.600
CH3COCH3 Acetone 12 A2 77 45 -32 1.718
C2H4+ Ethylene cation 4 Au 84 -324 -408 -0.259
CHONH2 formamide 12 A" 289 -75 -364 -3.825
CH3COCl Acetyl Chloride 15 A" 166 130 -36 1.278
C2F6 hexafluoroethane 4 A1u 68 50 -18 1.356
C3F8 perfluoropropane 13 A2 276 210 -66 1.315
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 59 -16 1.268
CH3COCH2CH3 2-Butanone 33 A" 87 18 -69 4.909
CH3COOCH3 methyl acetate 27 A" 110 54 -56 2.022
C3H6O 2-Propen-1-ol 24 A 188 110 -78 1.706
C5H8 Cyclopentene 18 A' 254 148 -106 1.715
C6F6 hexafluorobenzene 7 B2g 719 391 -328 1.839
NH2CN cyanamide 5 A' 408 612 204 0.667
C4H6O2 2,3-Butanedione 21 Bg 240 112 -128 2.150
C5H12 Propane, 2,2-dimethyl- 12 T1 203 290 87 0.700
C2H3NO3 Oxamic acid 3 A' 2600 3438 838 0.756
C2H3NO3 Oxamic acid 15 A' 328 259 -69 1.267
C2H3NO3 Oxamic acid 16 A" 984 773 -211 1.273
C2H3NO3 Oxamic acid 21 A" 162 60 -102 2.703
C3H6O Oxetane 18 B1 90 -17 -107 -5.207
C3O2 Carbon suboxide 7 Πu 61 115 54 0.528
HCNO fulminic acid 5 Π 224 -189 -413 -1.183
Zn(CH3)2 dimethyl zinc 2 A1' 1157 2913 1756 0.397
Zn(CH3)2 dimethyl zinc 3 A1' 503 1246 743 0.404
Zn(CH3)2 dimethyl zinc 11 E' 134 2979 2845 0.045
C5H8 1,4-Pentadiene 16 A 137 288 151 0.476
C5H8 1,4-Pentadiene 33 B 331 97 -234 3.400
HCCCl Chloroacetylene 5 Π 326 253 -73 1.287
C6H6 Benzvalene 10 A1 996 740 -256 1.345
C2F2 difluoroacetylene 4 Πg 270 183 -87 1.473
H2CS- thioformaldehyde anion 4 B1 450 -184 -634 -2.441
NaOH sodium hydroxide 3 Π 300 -119 -419 -2.525
C2H+ Ethynyl cation 3 Π 550 817 267 0.673
CH3OO methylperoxy radical 12 A" 170 134 -36 1.269
CH3 Methyl radical 2 A2" 606 416 -191 1.460
CH2OH Hydroxymethyl radical 8 A 482 690 208 0.699
CH2OH Hydroxymethyl radical 9 A 234 435 201 0.538
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 862 -274 1.317
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 141 -123 1.868
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 97 -261 3.706
HCCN cyanomethylene 5 Π 129 -383 -512 -0.336
C6H6 2,4-Hexadiyne 2 A1' 2265 2917 652 0.777
C6H6 2,4-Hexadiyne 3 A1' 1381 2232 851 0.619
C6H6 2,4-Hexadiyne 5 A1' 554 1238 684 0.448
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.643
C4H6 Methylenecyclopropane 17 B1 360 275 -85 1.311
C2Cl2 dichloroacetylene 4 Πg 333 213 -120 1.565
C2Cl2+ dichloroacetylene cation 5 Πu 233 171 -62 1.363
AsF5 Arsenic pentafluoride 6 E' 372 823 451 0.452
AsF5 Arsenic pentafluoride 7 E' 123 333 210 0.370
OClO- Chlorine dioxide anion 2 A1 418 327 -91 1.278
N2O4 Dinitrogen tetroxide 9 B2u 265 208 -57 1.271
N2O3 Dinitrogen trioxide 9 A" 63 148 85 0.425
C3O Tricarbon monoxide 5 Π 109 178 69 0.611
C3 carbon trimer 3 Πu 63 170 106 0.374
C5H5- cylopentadienyl anion 11 E2' 1020 2985 1965 0.342
C5H5- cylopentadienyl anion 12 E2' 854 1362 508 0.627
Cu2 Copper dimer 1 Σg 265 386 122 0.685
C5H5- cylopentadienyl anion 7 E1' 1003 1433 430 0.700
C5H5- cylopentadienyl anion 6 E1' 1455 3009 1554 0.483
ZnH2 Zinc hydride 3 Πu 633 496 -137 1.276
FO2 Dioxygen monofluoride 2 A' 579 1296 717 0.447
FO2 Dioxygen monofluoride 3 A' 376 556 180 0.676
OPCl Phosphorus oxychloride 2 A' 308 467 159 0.659
OPCl Phosphorus oxychloride 3 A' 492 283 -209 1.739
H2OH2O water dimer 7 A' 143 216 73 0.661
H2OH2O water dimer 11 A" 108 158 50 0.683
H2OH2O water dimer 12 A" 88 25 -63 3.523
Mg2 Magnesium diatomic 1 Σg 51 26 -25 1.957
Al2 Aluminum diatomic 1 Σg 286 208 -78 1.376
ZnCH3 Zinc monomethyl 6 E 315 594 279 0.530
ZnCN Zinc monocyanide 3 Π 212 64 -148 3.291