return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 MP2=FULL/6-311G**
Calculated values were scaled by 0.9486.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 377 118 0.687
CH3COOH Acetic acid 18 A" 93 71 -22 1.302
CH3OH Methyl alcohol 12 A" 200 330 130 0.606
C6H6 Benzene 8 B2g 703 391 -312 1.798
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 333 119 0.643
C2H4+ Ethylene cation 4 Au 84 -126 -210 -0.666
CHONH2 formamide 12 A" 289 -236 -525 -1.223
CBr2F2 Methane, dibromodifluoro- 3 A1 140 331 191 0.423
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 54 -21 1.381
CH3COOCH3 methyl acetate 27 A" 110 38 -72 2.862
CF2CCl2 difluorodichloroethylene 7 B1 1327 577 -750 2.299
CF2CCl2 difluorodichloroethylene 8 B1 989 318 -671 3.115
CF2CCl2 difluorodichloroethylene 11 B2 564 445 -119 1.267
CF2CCl2 difluorodichloroethylene 12 B2 323 182 -141 1.777
C9H8 Indene 40 A" 690 498 -192 1.387
C9H8 Indene 41 A" 549 376 -172 1.458
C6H5CN phenyl cyanide 19 B1 688 531 -157 1.297
C6H5CHO benzaldehyde 32 A" 688 411 -277 1.673
C6H4O2 parabenzoquinone 17 B2g 241 147 -94 1.635
C6H4O2 parabenzoquinone 30 B3u 109 82 -27 1.327
C3H6O 2-Propen-1-ol 24 A 188 111 -77 1.696
C6H5Cl chlorobenzene 18 B1 685 424 -261 1.615
C5H12 Pentane 23 A2 131 91 -40 1.441
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 A2 193 146 -47 1.320
C5H8 Cyclopentene 18 A' 254 182 -72 1.398
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 521 170 0.674
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 334 -875 3.617
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 408 -125 1.307
C6F6 hexafluorobenzene 7 B2g 715 340 -375 2.103
C6F6 hexafluorobenzene 8 B2g 243 126 -117 1.926
C6F6 hexafluorobenzene 20 E2u 175 128 -47 1.362
NH2CN cyanamide 5 A' 408 674 266 0.605
C4H6O2 2,3-Butanedione 21 Bg 240 121 -119 1.990
C4H2 Diacetylene 7 Πg 482 375 -107 1.284
C6H5F Fluorobenzene 18 B1 685 504 -181 1.359
CH3CCCH3 2-Butyne 16 E" 371 275 -96 1.349
C3H6O Oxetane 18 B1 90 -40 -130 -2.237
HCNO fulminic acid 5 Π 224 -303 -527 -0.740
C6H4F2 1,4-difluorobenzene 16 B2g 692 530 -162 1.305
C5H8 1,4-Pentadiene 16 A 137 290 153 0.473
C6H8 1,4-Cyclohexadiene 19 B1u 108 65 -43 1.653
C6H8 1,4-Cyclohexadiene 23 B2g 403 309 -94 1.303
CO+ carbon monoxide cation 1 Σ 2214 2735 521 0.810
CaO Calcium monoxide 1 Σ 732 507 -225 1.444
LiOH lithium hydroxide 3 Π 257 374 117 0.686
NaOH sodium hydroxide 3 Π 300 226 -74 1.326
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 212 68 0.679
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 321 -135 1.420
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 112 -59 1.520
CN Cyano radical 1 Σ 2069 2714 646 0.762
C2H Ethynyl radical 2 Σ 1841 2349 508 0.784
C2H Ethynyl radical 3 Π 372 801 429 0.464
CH3 Methyl radical 2 A2" 606 402 -204 1.508
CH2OH Hydroxymethyl radical 8 A 482 690 208 0.699
CH2OH Hydroxymethyl radical 9 A 234 442 208 0.530
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 855 -281 1.329
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 118 -146 2.229
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 88 -270 4.052
CH3CO Acetyl radical 4 A' 1420 3031 1611 0.468
CHCl2 dichloromethyl radical 4 A' 190 306 116 0.620
CH2CHO Vinyloxy radical 10 A" 703 1019 316 0.690
C4H6 Methylenecyclopropane 17 B1 360 261 -99 1.382
C2Cl2 dichloroacetylene 4 Πg 333 177 -156 1.878
O2+ diatomic oxygen cation 1 Σg 1906 1414 -492 1.348
FOOF Perfluoroperoxide 3 A 360 233 -127 1.544
FOOF Perfluoroperoxide 4 A 202 129 -73 1.567
CaF2 Calcium difluoride 2 A1 120 59 -61 2.036
ZnCl Zinc monochloride 1 Σ 391 300 -91 1.303
PCl5 Phosphorus pentachloride 2 A1' 370 266 -104 1.393
O3 Ozone 3 B2 1042 2156 1114 0.483
NO Nitric oxide 1 Σ 1904 3351 1447 0.568
NO2 Nitrogen dioxide 3 B2 1618 2382 764 0.679
N2O4 Dinitrogen tetroxide 9 B2u 265 196 -69 1.351
N2O3 Dinitrogen trioxide 9 A" 63 164 101 0.383
VO Vanadium monoxide 1 Σ 1011 1823 812 0.555
Li2O dilithium oxide 3 Πu 112 58 -53 1.912
FO Oxygen monofluoride 1 Σ 1053 2333 1280 0.451
C3 carbon trimer 3 Πu 63 173 109 0.367
CaOH Calcium monohydroxide 2 Σ 353 621 269 0.568
CaOH Calcium monohydroxide 3 Π 609 353 -256 1.725
PS phosphorus sulfide 1 Σ 739 1290 551 0.573
ClNO2 Nitryl chloride 3 A1 364 280 -84 1.300
SF5Cl sulfur chloropentafluoride 5 B1 625 457 -168 1.367
SF5Cl sulfur chloropentafluoride 7 B2 505 309 -196 1.634
SF5Cl sulfur chloropentafluoride 11 E 397 244 -153 1.628
PO Phosphorus monoxide 1 Σ 1233 3549 2316 0.348
AlO Aluminum monoxide 1 Σ 979 745 -234 1.314
C2H4O4 Formic acid dimer 13 Au 1050 66 -984 15.892
SCN thiocyanato radical 1 Σ 1942 2408 466 0.807
ClOO chloroperoxy radical 2 A' 414 1058 645 0.391
ClOO chloroperoxy radical 3 A' 201 488 286 0.413
H2POH Phosphinous acid 9 A" 375 261 -114 1.435
AsN Arsenic mononitride 1 Σ 1069 827 -242 1.293
Mg2 Magnesium diatomic 1 Σg 51 29 -22 1.752
ClOF3 Chlorine trifluoride oxide 5 A' 319 248 -71 1.286
ZnCH3 Zinc monomethyl 6 E 315 599 284 0.526
CH3BO Borane, methyloxo- 7 E 897 1405 509 0.638
ONONO Nitrosyl nitrite 9 B2 380 221 -159 1.722