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 B3LYP/CEP-121G*
Calculated values were scaled by 0.9694.

Species Name mode Symmetry Experiment Theory difference ratio
C2H6O2S Dimethyl sulfone 20 B1 262 195 -67 1.341
CH3CONH2 Acetamide 20 A 259 209 -50 1.240
CH3COOH Acetic acid 18 A" 93 65 -28 1.421
CH3OH Methyl alcohol 12 A" 200 324 124 0.617
C3H4O2 β–Propiolactone 21 A" 113 172 59 0.656
C2H4+ Ethylene cation 4 Au 84 -383 -467 -0.220
CHONH2 formamide 12 A" 289 -113 -402 -2.552
C3F8 perfluoropropane 13 A2 276 213 -63 1.296
CH3COOCH3 methyl acetate 27 A" 110 34 -76 3.278
C5H12 Pentane 23 A2 131 103 -28 1.266
C4H8S Thiophene, tetrahydro- 5 A 1464 2946 1482 0.497
C4H8S Thiophene, tetrahydro- 6 A 1441 2946 1505 0.489
C4H8S Thiophene, tetrahydro- 7 A 1321 2929 1608 0.451
C4H8S Thiophene, tetrahydro- 8 A 1276 2926 1650 0.436
C4H8S Thiophene, tetrahydro- 11 A 1023 1446 423 0.707
C4H8S Thiophene, tetrahydro- 12 A 888 1445 557 0.615
C4H8S Thiophene, tetrahydro- 13 A 829 1320 491 0.628
C4H8S Thiophene, tetrahydro- 14 A 822 1294 472 0.635
C4H8S Thiophene, tetrahydro- 15 A 678 1267 589 0.535
C4H8S Thiophene, tetrahydro- 16 A 472 1243 771 0.380
C4H8S Thiophene, tetrahydro- 17 A 290 1197 907 0.242
C3H6O 2-Propen-1-ol 24 A 188 110 -79 1.717
C5H8 Cyclopentene 18 A' 254 137 -117 1.858
C2H3N3 1H-1,2,4-Triazole 18 A" 640 501 -139 1.278
C4H6O2 2,3-Butanedione 9 Ag 614 495 -119 1.241
C4H6O2 2,3-Butanedione 21 Bg 240 101 -139 2.387
C4H2 Diacetylene 6 Πg 627 1350 723 0.464
C4H2 Diacetylene 7 Πg 482 690 208 0.698
C5H12 Propane, 2,2-dimethyl- 12 T1 203 298 95 0.681
NH2CN cyanamide 5 A' 408 632 224 0.646
C2H3NO3 Oxamic acid 20 A" 315 242 -73 1.303
C2H3NO3 Oxamic acid 21 A" 162 46 -116 3.507
C3H6O Oxetane 18 B1 90 64 -25 1.392
C6H4 Benzyne 24 B2 472 354 -118 1.334
C6F6 hexafluorobenzene 7 B2g 719 516 -203 1.394
C2H3NO3 Oxamic acid 3 A' 2600 3464 864 0.751
C2H3NO3 Oxamic acid 15 A' 328 254 -74 1.293
C2H3NO3 Oxamic acid 16 A" 984 780 -204 1.262
C2H3NO3 Oxamic acid 17 A" 815 642 -173 1.268
C2H3NO3 Oxamic acid 18 A" 745 602 -143 1.238
C3O2 Carbon suboxide 7 Πu 61 172 111 0.355
C5H8 1,4-Pentadiene 16 A 137 288 151 0.475
HCNO fulminic acid 5 Π 224 122 -102 1.842
C6H6 Benzvalene 10 A1 996 731 -265 1.362
C2F2 difluoroacetylene 4 Πg 270 179 -91 1.507
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.696
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 346 -110 1.318
H2CS- thioformaldehyde anion 4 B1 450 -143 -593 -3.145
C4H9N Cyclobutylamine 21 A' 174 140 -34 1.242
C2H+ Ethynyl cation 3 Π 550 787 238 0.698
SiF2+ Silicon difluoride cation 2 A1 350 267 -83 1.312
NaOH sodium hydroxide 3 Π 300 207 -93 1.447
CH3OO methylperoxy radical 12 A" 170 127 -43 1.338
CH2OH Hydroxymethyl radical 9 A 234 418 184 0.560
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 856 -280 1.327
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 153 -111 1.727
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 104 -254 3.455
HCCN cyanomethylene 5 Π 129 -278 -407 -0.464
CH3 Methyl radical 2 A2" 606 451 -156 1.346
CHCl2 dichloromethyl radical 4 A' 190 284 94 0.669
C4H6 Methylenecyclopropane 17 B1 360 283 -77 1.274
MgF2 Magnesium fluoride 3 Πu 165 128 -37 1.288
C2Cl2 dichloroacetylene 4 Πg 333 244 -89 1.362
FNO3 Fluorine nitrate 7 A' 303 448 145 0.677
PCl5 Phosphorus pentachloride 7 E' 100 79 -21 1.268
C3 carbon trimer 3 Πu 63 301 238 0.210
C4 Carbon tetramer 4 Πg 323 525 202 0.616
ClFO3 Perchloryl fluoride 6 E 405 318 -87 1.272
N2O3 Dinitrogen trioxide 9 A" 63 127 64 0.497
SF5 Sulfur pentafluoride 9 E 387 302 -85 1.283
OClO- Chlorine dioxide anion 2 A1 418 310 -108 1.349
C3O Tricarbon monoxide 5 Π 109 248 139 0.439
H2POH Phosphinous acid 9 A" 375 238 -138 1.579
ClOO chloroperoxy radical 2 A' 414 261 -152 1.583
ClOO chloroperoxy radical 3 A' 201 104 -97 1.935
SiH- silicon monohydride anion 1 Σ 2175 1712 -463 1.270
H2OH2O water dimer 12 A" 88 58 -30 1.526
OPCl Phosphorus oxychloride 3 A' 492 281 -211 1.750
OPCl Phosphorus oxychloride 2 A' 308 465 157 0.662
Cl3- trichloride anion 2 Σu 327 264 -63 1.241