return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

19 02 11 15 45

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 wB97X-D/cc-pVTZ
Calculated values were scaled by 0.956.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 164 51 0.688
CH3CONH2 Acetamide 20 A 259 152 -107 1.706
CH3COOH Acetic acid 18 torsion A" 93 -120 -213 -0.776
CH3OH Methyl alcohol 12 torsion A" 200 288 88 0.693
C2H6O2S Dimethyl sulfone 20 B1 262 203 -59 1.291
CH3CHO+ acetaldehyde cation 15 A" 145 67 -78 2.153
CHONH2 formamide 12 torsion A" 289 219 -70 1.320
CH3CH(CH3)CH3 Isobutane 12 A2 198 138 -60 1.432
CH3CH(CH3)CH3 Isobutane 24 E 280 206 -74 1.359
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 21 -54 3.644
CH3COCH2CH3 2-Butanone 31 torsion A" 201 148 -53 1.358
CH3COCH2CH3 2-Butanone 32 torsion A" 106 -59 -165 -1.797
CH3COCH2CH3 2-Butanone 33 torsion A" 87 -135 -222 -0.644
CH3COOCH3 methyl acetate 26 torsion A" 136 92 -44 1.486
CH3COOCH3 methyl acetate 27 torsion A" 110 -133 -243 -0.828
C6H4Cl2 1,4-dichlorobenzene 30 B3u 122 97 -25 1.261
CH3CH2CH2Br n-propyl bromide 27 torsion A" 133 96 -37 1.389
C3H6O 2-Propen-1-ol 24 A 188 116 -73 1.629
CH2ClCHO chloroacetaldehyde 15 torsion A 27 55 28 0.493
CH2ClCHO chloroacetaldehyde 15 A" 59 149 90 0.397
C5H12 Pentane 23 A2 131 79 -52 1.655
C5H12 Pentane 33 B1 88 127 39 0.695
CH3SCH3+ dimethyl sulfide cation 15 B1 172 113 -59 1.517
C2H4+ Ethylene cation 4 torsion Au 84 -434 -518 -0.194
C4H10O Ethoxy ethane 20 A2 137 60 -77 2.293
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 torsion A2 193 124 -69 1.562
C3F6 hexafluoropropene 21 A" 60 34 -26 1.745
C4H9N Pyrrolidine 36 A" 65 99 34 0.658
C4H8O2 1,4-Dioxane 19 Au 288 226 -62 1.277
C5H8 Cyclopentene 18 torsion A' 254 153 -101 1.662
C4H8 cyclobutane 6 torsion A1 199 154 -45 1.291
CH3CHFCH3 2-Fluoropropane 27 A" 243 180 -63 1.352
C4H6O2 2,3-Butanedione 16 torsion Au 48 -70 -118 -0.683
C4H6O2 2,3-Butanedione 21 torsion Bg 240 -53 -293 -4.506
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 1002 -389 1.388
C5H12 Propane, 2,2-dimethyl- 4 A2 198 290 92 0.683
C5H12 Propane, 2,2-dimethyl- 12 T1 203 347 144 0.586
C2H3NO3 Oxamic acid 3 A' 2600 3469 869 0.749
C2H3NO3 Oxamic acid 17 A" 815 646 -169 1.261
C2H3NO3 Oxamic acid 21 A" 162 59 -103 2.744
C3H6O Oxetane 18 B1 90 -77 -167 -1.160
C3O2 Carbon suboxide 7 Πu 61 -18 -79 -3.304
CH3OC2H5 Ethane, methoxy- 29 A" 248 173 -75 1.433
CH3COF Acetyl fluoride 15 torsion A" 123 -79 -202 -1.561
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 666 -2413 4.624
C5H8 1,4-Pentadiene 16 A 137 271 134 0.506
C5H8 1,4-Pentadiene 17 torsion A 102 63 -39 1.615
C5H8 1,4-Pentadiene 17 torsion A 102 63 -39 1.615
C5H8 1,4-Pentadiene 33 torsion B 331 91 -240 3.636
C6H6 Benzvalene 10 A1 996 751 -245 1.327
C6H10 2-Hexyne 41 A" 88 17 -71 5.099
C5H8O Methyl cyclopropyl ketone 35 A" 125 46 -79 2.713
C5H8O Methyl cyclopropyl ketone 36 A" 61 -30 -91 -2.001
H2CS- thioformaldehyde anion 4 B1 450 207 -243 2.177
NaOH sodium hydroxide 3 torsion Π 300 222 -78 1.353
SiF2+ Silicon difluoride cation 2 A1 350 277 -73 1.264
CFCl2 dichlorofluoromethyl radical 2 A' 747 581 -166 1.287
C2H+ Ethynyl cation 3 Π 550 918 369 0.598
CH3OO methylperoxy radical 12 torsion A" 170 89 -81 1.915
C4H9N Cyclobutylamine 21 A' 174 138 -36 1.262
CH2OH Hydroxymethyl radical 9 torsion A 234 403 169 0.581
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.317
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 126 -138 2.101
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 68 -290 5.276
HCCN cyanomethylene 5 Π 129 -297 -426 -0.434
CHCl2 dichloromethyl radical 4 A' 190 291 101 0.654
C4H6 Methylenecyclopropane 17 B1 360 280 -80 1.285
CH2Cl chloromethyl radical 4 B1 402 177 -225 2.270
BF3+ boron trifluoride cation 5 B2 1791 677 -1114 2.645
CaBr2 Calcium dibromide 3 Πu 72 29 -43 2.484
N2O3 Dinitrogen trioxide 9 torsion A" 63 135 72 0.465
AsSe Arsenic monoselenide 1 Σ 280 414 134 0.676
BCl3+ Boron Trichloride cation 3 E' 1104 753 -351 1.467
SiC2 Silicon dicarbide 3 B2 196 143 -54 1.376
S3 Sulfur trimer 2 A1 281 600 319 0.468
Br3- tribromide anion 2 Σu 214 142 -72 1.503
ClOO chloroperoxy radical 2 A' 414 229 -184 1.803
ClOO chloroperoxy radical 3 A' 201 93 -109 2.171
Cl3- trichloride anion 2 Σu 327 218 -109 1.498
B5H9 pentaborane9 13 B1 240 585 345 0.410
B5H9 pentaborane9 16 B2 1036 787 -249 1.316
B5H9 pentaborane9 22 E 1409 1037 -372 1.358
OPCl Phosphorus oxychloride 2 A' 308 491 183 0.628
OPCl Phosphorus oxychloride 3 A' 492 300 -192 1.640
H2OH2O water dimer 8 A' 103 154 51 0.667
H2POH Phosphinous acid 9 A" 375 273 -102 1.376
CHFCl Chlorofluoromethyl radical 6 A 540 394 -146 1.371
ZnCH3 Zinc monomethyl 6 E 315 572 257 0.551
NH2NN+ hydrazoic acid, protonated 6 A' 489 324 -165 1.509
H2CNCN cyanamide, methylene 3 A' 2208 2954 746 0.747
H2CNCN cyanamide, methylene 4 A' 1621 2252 631 0.720
C2H3NO Nitrosoethylene 11 A' 490 339 -151 1.446
SNO Nitrogen oxide sulfide 3 A' 792 492 -301 1.612