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 mPW1PW91/6-31+G**
Calculated values were scaled by 0.9518.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 175 62 0.645
CH3COOH Acetic acid 18 A" 93 66 -27 1.412
CH3OH Methyl alcohol 12 A" 200 304 104 0.658
C2H4+ Ethylene cation 4 Au 84 -428 -512 -0.196
CH3COCl Acetyl Chloride 15 A" 166 125 -41 1.331
C3F8 perfluoropropane 13 A2 276 211 -65 1.307
CH3COOCH3 methyl acetate 27 A" 110 33 -77 3.373
C3H6O 2-Propen-1-ol 24 A 188 110 -78 1.715
C4H8S Thiophene, tetrahydro- 5 A 1464 2944 1480 0.497
C4H8S Thiophene, tetrahydro- 6 A 1441 2944 1503 0.489
C4H8S Thiophene, tetrahydro- 7 A 1321 2927 1606 0.451
C4H8S Thiophene, tetrahydro- 8 A 1276 2926 1650 0.436
C4H8S Thiophene, tetrahydro- 12 A 888 1415 527 0.627
C4H8S Thiophene, tetrahydro- 13 A 829 1304 475 0.636
C4H8S Thiophene, tetrahydro- 14 A 822 1280 458 0.642
C4H8S Thiophene, tetrahydro- 15 A 678 1256 578 0.540
C4H8S Thiophene, tetrahydro- 16 A 472 1234 762 0.383
C4H8S Thiophene, tetrahydro- 17 A 290 1190 900 0.244
C5H8 Cyclopentene 18 A' 254 146 -108 1.739
C4H6O2 2,3-Butanedione 21 Bg 240 99 -141 2.427
C5H12 Propane, 2,2-dimethyl- 12 T1 203 301 98 0.673
C2H3NO3 Oxamic acid 3 A' 2600 3462 862 0.751
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.281
C2H3NO3 Oxamic acid 21 A" 162 65 -97 2.509
C3H6O Oxetane 18 B1 90 19 -71 4.770
C3O2 Carbon suboxide 7 Πu 61 156 95 0.392
C5H8 1,4-Pentadiene 16 A 137 285 148 0.481
HCCBr bromoacetylene 5 Π 295 447 152 0.660
C6H6 Benzvalene 10 A1 996 741 -255 1.344
H2CS- thioformaldehyde anion 4 B1 450 285 -165 1.580
SiF2+ Silicon difluoride cation 2 A1 350 270 -80 1.296
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 343 -113 1.329
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 134 -37 1.280
CH3OO methylperoxy radical 12 A" 170 130 -40 1.307
CH2OH Hydroxymethyl radical 9 A 234 401 167 0.583
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 862 -274 1.318
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 140 -124 1.886
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 97 -261 3.679
HCCN cyanomethylene 5 Π 129 -268 -397 -0.481
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.644
C4H6 Methylenecyclopropane 17 B1 360 283 -77 1.272
N2O3 Dinitrogen trioxide 9 A" 63 131 68 0.482
C3O Tricarbon monoxide 5 Π 109 186 77 0.587
C3 carbon trimer 3 Πu 63 148 85 0.428
TiO2 Titanium dioxide 1 A1 959 332 -627 2.887
H3O+ hydronium cation 2 A1 954 746 -209 1.280
FO2 Dioxygen monofluoride 3 A' 376 229 -147 1.643
ClOO chloroperoxy radical 2 A' 414 266 -147 1.553
ClOO chloroperoxy radical 3 A' 201 111 -90 1.813
Cl3- trichloride anion 2 Σu 327 257 -70 1.274
OPCl Phosphorus oxychloride 2 A' 308 480 172 0.641
OPCl Phosphorus oxychloride 3 A' 492 292 -200 1.683
F3- trifluoride anion 2 Σu 550 428 -122 1.284
H2POH Phosphinous acid 9 A" 375 257 -119 1.462
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597
ZnCH3 Zinc monomethyl 6 E 315 585 270 0.538