return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Vibrations > Bad Calculations > Bad vib. Calc. vs exp. OR Resources > Bad Calculations > Vibrations > Bad vib. Calc. vs exp.

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 mPW1PW91/6-31G*
Calculated values were scaled by 0.9483.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 174 61 0.648
CH3CONH2 Acetamide 20 A 259 137 -122 1.894
CH3COOH Acetic acid 18 A" 93 73 -20 1.277
CH3OH Methyl alcohol 12 A" 200 329 129 0.608
CH3COCH3 Acetone 12 A2 77 21 -56 3.740
C2H4+ Ethylene cation 4 Au 84 -391 -476 -0.215
CHONH2 formamide 12 A" 289 146 -143 1.975
C2F6 hexafluoroethane 4 A1u 68 47 -21 1.456
C3F8 perfluoropropane 13 A2 276 207 -69 1.335
CH3COOCH3 methyl acetate 27 A" 110 50 -60 2.188
C3H6O 2-Propen-1-ol 24 A 188 111 -77 1.688
C4H8S Thiophene, tetrahydro- 5 A 1464 2942 1478 0.498
C4H8S Thiophene, tetrahydro- 6 A 1441 2942 1501 0.490
C4H8S Thiophene, tetrahydro- 7 A 1321 2925 1604 0.452
C4H8S Thiophene, tetrahydro- 8 A 1276 2925 1649 0.436
C4H8S Thiophene, tetrahydro- 11 A 1023 1435 411 0.713
C4H8S Thiophene, tetrahydro- 12 A 888 1433 545 0.620
C4H8S Thiophene, tetrahydro- 13 A 829 1315 486 0.630
C4H8S Thiophene, tetrahydro- 14 A 822 1291 469 0.637
C4H8S Thiophene, tetrahydro- 15 A 678 1266 588 0.536
C4H8S Thiophene, tetrahydro- 16 A 472 1242 770 0.380
C4H8S Thiophene, tetrahydro- 17 A 290 1198 908 0.242
C5H8 Cyclopentene 18 A' 254 140 -114 1.818
C6F6 hexafluorobenzene 7 B2g 719 511 -208 1.408
C4H6O2 2,3-Butanedione 21 Bg 240 104 -136 2.302
C5H12 Propane, 2,2-dimethyl- 12 T1 203 301 98 0.674
C2H3NO3 Oxamic acid 3 A' 2600 3451 851 0.753
C2H3NO3 Oxamic acid 15 A' 328 255 -73 1.284
C2H3NO3 Oxamic acid 21 A" 162 66 -96 2.438
C3H6O Oxetane 18 B1 90 48 -42 1.883
C3O2 Carbon suboxide 7 Πu 61 114 53 0.537
C5H8 1,4-Pentadiene 16 A 137 283 146 0.484
CH3ONO Methyl nitrite 15 A" 186 116 -70 1.601
C6H6 Benzvalene 10 A1 996 743 -253 1.341
H2CS- thioformaldehyde anion 4 B1 450 -79 -529 -5.667
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.694
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.336
CH3OO methylperoxy radical 12 A" 170 134 -36 1.268
CH3 Methyl radical 2 A2" 606 433 -173 1.399
CH2OH Hydroxymethyl radical 9 A 234 421 187 0.555
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.316
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 147 -117 1.793
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 99 -259 3.617
HCCN cyanomethylene 5 Π 129 -296 -425 -0.435
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.644
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.279
N2O3 Dinitrogen trioxide 9 A" 63 140 77 0.451
C3O Tricarbon monoxide 5 Π 109 174 65 0.628
C3 carbon trimer 3 Πu 63 141 78 0.449
TiO2 Titanium dioxide 1 A1 959 339 -620 2.832
ZnH2 Zinc hydride 3 Πu 633 491 -142 1.289
ClOO chloroperoxy radical 2 A' 414 277 -136 1.492
ClOO chloroperoxy radical 3 A' 201 121 -81 1.671
OPCl Phosphorus oxychloride 2 A' 308 483 175 0.637
OPCl Phosphorus oxychloride 3 A' 492 291 -201 1.688
H2OH2O water dimer 7 A' 143 220 77 0.650
H2OH2O water dimer 11 A" 108 167 59 0.647
H2OH2O water dimer 12 A" 88 65 -23 1.359
H2POH Phosphinous acid 9 A" 375 252 -123 1.487
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597
ZnCH3 Zinc monomethyl 6 E 315 592 277 0.532
ZnCN Zinc monocyanide 3 Π 212 67 -145 3.145