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 B1B95/3-21G
Calculated values were scaled by 0.9567.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 392 133 0.661
CH3OH Methyl alcohol 12 A" 200 369 169 0.542
HNCO Isocyanic acid 4 A' 777 573 -203 1.354
HNCO Isocyanic acid 5 A' 577 413 -164 1.398
C2H4+ Ethylene cation 4 Au 84 -532 -616 -0.158
CHONH2 formamide 12 A" 289 499 210 0.579
C3F8 perfluoropropane 9 A1 151 216 65 0.700
C3F8 perfluoropropane 13 A2 276 195 -81 1.418
C2H2O2 Ethanedial 7 Au 127 195 68 0.653
C3H6O 2-Propen-1-ol 22 A 377 294 -84 1.285
C3H6O 2-Propen-1-ol 24 A 188 100 -88 1.883
C4H9N Pyrrolidine 36 A" 65 28 -37 2.313
C4H8O2 1,4-Dioxane 19 Au 288 219 -69 1.313
C5H8 Cyclopentene 18 A' 254 133 -121 1.912
C5H12 Propane, 2,2-dimethyl- 12 T1 203 311 108 0.653
C2H3NO3 Oxamic acid 21 A" 162 116 -46 1.394
N2H4 Hydrazine 6 A 780 596 -184 1.310
C4H6O2 2,3-Butanedione 21 Bg 240 105 -135 2.288
C2N2 Cyanogen 4 Πg 503 756 253 0.665
C2H3NO3 Oxamic acid 3 A' 2600 3375 775 0.770
C2H3NO3 Oxamic acid 15 A' 328 246 -82 1.334
C3O2 Carbon suboxide 7 Πu 61 145 84 0.420
HCNO fulminic acid 5 Π 224 528 304 0.424
C3H6O Oxetane 23 B2 1228 963 -265 1.275
C5H8 1,4-Pentadiene 16 A 137 299 162 0.459
C5H8 1,4-Pentadiene 17 A 102 80 -22 1.276
C6H6 Benzvalene 10 A1 996 786 -210 1.267
LiOH lithium hydroxide 3 Π 257 410 153 0.626
H2CS- thioformaldehyde anion 4 B1 450 237 -213 1.901
C4N2 2-Butynedinitrile 6 Πg 504 909 405 0.554
C4N2 2-Butynedinitrile 8 Πu 472 683 211 0.691
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 210 66 0.687
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 344 -112 1.326
FCO+ Carbonyl fluoride cation 3 Π 650 501 -149 1.299
C2H Ethynyl radical 3 Π 372 542 171 0.685
CH3 Methyl radical 2 A2" 606 465 -141 1.304
HCCN cyanomethylene 5 Π 129 381 252 0.339
HCCN cyanomethylene 4 Π 383 592 209 0.647
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 100 -258 3.596
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 145 -119 1.818
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 864 -272 1.315
CH2OH Hydroxymethyl radical 9 A 234 425 191 0.551
OH- hydroxide anion 1 Σ 3738 2659 -1079 1.406
OH Hydroxyl radical 1 Σ 3738 3155 -582 1.185
NF2 Difluoroamino radical 2 A1 573 455 -118 1.258
HF Hydrogen fluoride 1 Σ 4138 3535 -603 1.171
O2+ diatomic oxygen cation 1 Σg 1906 1434 -472 1.329
NF3 Nitrogen trifluoride 4 E 492 386 -106 1.274
N2O4 Dinitrogen tetroxide 9 B2u 265 204 -61 1.297
N2O3 Dinitrogen trioxide 9 A" 63 157 94 0.400
C3O Tricarbon monoxide 5 Π 109 193 84 0.566
Li2O dilithium oxide 3 Πu 112 71 -40 1.565
ND3 Ammonia-d3 2 A1 748 521 -227 1.436
NH2- amino anion 1 A1 3122 2583 -539 1.209
NH2- amino anion 3 B2 3190 2624 -566 1.216
H3O+ hydronium cation 2 A1 954 485 -469 1.966
H2O2 Hydrogen peroxide 4 A 371 77 -294 4.821
NH3 Ammonia 2 A1 950 682 -268 1.393
C3 carbon trimer 3 Πu 63 158 95 0.401
FOOF Perfluoroperoxide 1 A 1210 958 -252 1.264
FOOF Perfluoroperoxide 4 A 202 161 -41 1.258
FOOF Perfluoroperoxide 5 B 614 940 326 0.653
BeF2 Beryllium fluoride 3 Πu 343 252 -90 1.358
O3 Ozone 2 A1 705 559 -146 1.262
ONONO Nitrosyl nitrite 9 B2 380 604 224 0.629
C2H4O4 Formic acid dimer 24 Bu 268 404 136 0.664
OPCl Phosphorus oxychloride 2 A' 308 479 171 0.644
OPCl Phosphorus oxychloride 3 A' 492 294 -198 1.676
H2OH2O water dimer 11 A" 108 218 110 0.495
H2OH2O water dimer 10 A" 523 854 331 0.612
H2OH2O water dimer 8 A' 103 202 99 0.509
H2OH2O water dimer 7 A' 143 278 135 0.515
H2OH2O water dimer 6 A' 311 528 217 0.589
C2H4O4 Formic acid dimer 2 Ag 2949 2188 -761 1.348