return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 QCISD/3-21G*
Calculated values were scaled by 0.9611.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 363 163 0.551
C2H4+ Ethylene cation 4 Au 84 -347 -432 -0.242
HNCO Isocyanic acid 4 A' 777 594 -183 1.308
CBr2F2 Methane, dibromodifluoro- 3 A1 140 326 186 0.430
C3F8 perfluoropropane 13 A2 276 202 -74 1.364
CH3COOCH3 methyl acetate 26 A" 136 101 -35 1.352
CF2CCl2 difluorodichloroethylene 7 B1 1327 602 -725 2.205
CF2CCl2 difluorodichloroethylene 8 B1 989 321 -668 3.076
CF2CCl2 difluorodichloroethylene 11 B2 564 444 -120 1.269
CF2CCl2 difluorodichloroethylene 12 B2 323 177 -146 1.830
C3H6O 2-Propen-1-ol 22 A 377 299 -78 1.261
C3H6O 2-Propen-1-ol 24 A 188 89 -99 2.108
C5H8 Cyclopentene 18 A' 254 115 -139 2.201
CH2N4 1H-Tetrazole 11 A' 925 697 -228 1.328
C2H2N4 sym-tetrazine 13 B2u 883 411 -472 2.148
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 553 202 0.635
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 343 -866 3.527
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 381 -152 1.399
C4H6O2 2,3-Butanedione 16 Au 48 72 24 0.670
C4H6O2 2,3-Butanedione 21 Bg 240 97 -143 2.487
C4H2 Diacetylene 7 Πg 482 -636 -1118 -0.758
C4H2 Diacetylene 9 Πu 231 128 -103 1.799
C2H3NO3 Oxamic acid 3 A' 2600 3363 763 0.773
C2H3NO3 Oxamic acid 15 A' 328 258 -70 1.272
C2H3NO3 Oxamic acid 17 A" 815 628 -187 1.298
C2H3NO3 Oxamic acid 21 A" 162 106 -56 1.526
C3H6O Oxetane 7 A1 1018 803 -215 1.268
C3H6O Oxetane 18 B1 90 67 -23 1.344
C3H6O Oxetane 23 B2 1228 921 -307 1.333
HCNO fulminic acid 3 Σ 1254 922 -332 1.360
HCNO fulminic acid 5 Π 224 454 230 0.493
Zn(CH3)2 dimethyl zinc 11 E' 134 -95 -229 -1.414
C5H8 1,4-Pentadiene 16 A 137 295 158 0.465
C5H8 1,4-Pentadiene 17 A 102 78 -24 1.306
C6H8 1,4-Cyclohexadiene 19 B1u 108 80 -28 1.351
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 223 79 0.645
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 335 -121 1.361
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 111 -60 1.547
CCl2 dichloromethylene 3 B2 758 591 -167 1.282
FCO+ Carbonyl fluoride cation 3 Π 650 453 -197 1.434
CH3 Methyl radical 2 A2" 606 481 -125 1.260
CH2OH Hydroxymethyl radical 9 A 234 419 185 0.558
H2CCCCH2 Butatriene 10 B2g 544 297 -247 1.830
H2CCCCH2 Butatriene 16 B3g 330 259 -71 1.274
OH- hydroxide anion 1 Σ 3738 2496 -1243 1.498
OH Hydroxyl radical 1 Σ 3738 3097 -641 1.207
CHCl2 dichloromethyl radical 4 A' 190 293 103 0.648
HClO4 perchloric acid 12 A" 191 28 -163 6.884
HF Hydrogen fluoride 1 Σ 4138 3537 -601 1.170
H2O2 Hydrogen peroxide 4 A 371 121 -250 3.073
H2O Water 1 A1 3657 2374 -1283 1.540
H2O Water 3 B2 3756 2552 -1204 1.472
O2+ diatomic oxygen cation 1 Σg 1906 1210 -696 1.575
HNO2 Nitrous acid 2 A' 1700 1350 -350 1.259
HN3 hydrogen azide 4 A' 1151 921 -229 1.249
FOOF Perfluoroperoxide 1 A 1210 847 -363 1.428
FOOF Perfluoroperoxide 4 A 202 135 -67 1.493
BeF2 Beryllium fluoride 3 Πu 343 259 -83 1.321
ClF+ clorine monofluoride cation 1 Σ 870 656 -214 1.326
N2O Nitrous oxide 2 Σ 1298 933 -365 1.391
N2O Nitrous oxide 3 Π 596 439 -157 1.357
NO Nitric oxide 1 Σ 1904 1437 -467 1.325
NO2 Nitrogen dioxide 1 A1 1318 978 -340 1.348
NO2 Nitrogen dioxide 3 B2 1618 657 -961 2.464
Li2O dilithium oxide 3 Πu 112 53 -59 2.115
C3 carbon trimer 3 Πu 63 -176 -239 -0.361
PO2 Phosphorus dioxide 3 B2 1328 794 -533 1.671
BrNO Nitrosyl bromide 1 A' 1832 1283 -550 1.428
CuH Copper monohydride 1 Σ 1941 1459 -483 1.331
NH2- amino anion 1 A1 3122 2478 -644 1.260
NH2- amino anion 3 B2 3190 2513 -677 1.270
KrF2 Krypton difluoride 1 Σg 449 350 -99 1.283
SF5Cl sulfur chloropentafluoride 5 B1 625 478 -147 1.307
SF5Cl sulfur chloropentafluoride 7 B2 505 330 -175 1.532
SF5Cl sulfur chloropentafluoride 11 E 397 259 -138 1.530
HOClO Chlorous acid 3 A 978 729 -249 1.342
HOClO Chlorous acid 4 A 592 428 -163 1.382
H3O+ hydronium cation 2 A1 954 272 -682 3.505
ClONO2 Chlorine nitrate 1 A' 1737 1262 -474 1.376
ClONO2 Chlorine nitrate 9 A" 124 97 -27 1.275
Cl3- trichloride anion 2 Σu 327 261 -66 1.254
Na2 Sodium diatomic 1 Σg 159 121 -38 1.318
H2POH Phosphinous acid 9 A" 375 210 -165 1.785
Mg2 Magnesium diatomic 1 Σg 51 30 -21 1.709
BrONO2 Bromine nitrate 1 A' 1714 1252 -462 1.369
BrONO2 Bromine nitrate 8 A" 728 579 -149 1.258
ZnCH3 Zinc monomethyl 6 E 315 605 290 0.521
ClONO chlorine nitrite 1 A' 1715 1314 -401 1.305
CH3BO Borane, methyloxo- 7 E 897 1482 585 0.605
BrONO Bromine nitrite 1 A' 1723 1322 -402 1.304
ONONO Nitrosyl nitrite 1 A1 1740 1331 -409 1.307
ONONO Nitrosyl nitrite 6 B1 140 103 -37 1.364
ONONO Nitrosyl nitrite 7 B2 1697 1275 -422 1.331
ONONO Nitrosyl nitrite 9 B2 380 575 195 0.661