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/CEP-121G*
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 torsion A" 200 351 151 0.570
C2H2+ acetylene cation 4 Πg 572 832 260 0.688
CH3CHO+ acetaldehyde cation 15 A" 145 91 -54 1.585
CH3SCH3+ dimethyl sulfide cation 15 B1 172 139 -33 1.240
C(CH3)3SH 2-Propanethiol, 2-methyl- 39 A" 190 144 -46 1.319
C6H4Cl2 1,4-dichlorobenzene 30 B3u 122 101 -21 1.205
CH3CH2CH2CH3 Butane 5 Ag 1442 427 -1015 3.375
CH3CH2CH2CH3 Butane 8 Ag 1151 849 -302 1.356
CH3CH2CH2CH3 Butane 36 Bu 271 3116 2845 0.087
CHSNH2 thioformamide 12 A" 393 324 -69 1.212
C3F6 hexafluoropropene 21 A" 60 27 -33 2.212
CH3CH2CHO Propanal 24 torsion A" 135 106 -29 1.273
CF3CHF2 pentafluoroethane 18 torsion A" 75 55 -20 1.360
CH3CHFCH3 2-Fluoropropane 27 A" 243 201 -42 1.209
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 1046 -345 1.330
CH2FCH2CH3 1-Fluoropropane 22 A" 890 1283 393 0.694
C3O2 Carbon suboxide 7 Πu 61 173 112 0.352
CH3F Methyl fluoride 5 E 1467 3141 1674 0.467
C6H6 Benzvalene 10 A1 996 782 -214 1.273
H2CS- thioformaldehyde anion 4 B1 450 116 -334 3.867
SiF2+ Silicon difluoride cation 2 A1 350 278 -72 1.260
CFCl2 dichlorofluoromethyl radical 2 A' 747 616 -131 1.213
C2H5 Ethyl radical 9 A' 528 431 -97 1.226
CHCl2 dichloromethyl radical 4 A' 190 301 111 0.632
CH2Cl chloromethyl radical 4 B1 402 -70 -472 -5.720
OClO- Chlorine dioxide anion 2 A1 418 332 -86 1.260
BCl3+ Boron Trichloride cation 3 E' 1104 769 -335 1.436
C3O Tricarbon monoxide 5 Π 109 242 133 0.450
C3 carbon trimer 3 Πu 63 302 238 0.210
C4 Carbon tetramer 4 Πg 323 553 230 0.584
C4 Carbon tetramer 5 Πu 160 250 90 0.640
S3 Sulfur trimer 2 A1 281 631 350 0.446
SiH2D2 silane-d2 6 B1 2183 1636 -547 1.334
SiH2D2 silane-d2 8 B2 1601 2263 662 0.707
B5H9 pentaborane9 13 B1 240 620 380 0.387
B5H9 pentaborane9 16 B2 1036 804 -232 1.288
B5H9 pentaborane9 18 B2 600 495 -105 1.213
B5H9 pentaborane9 22 E 1409 1095 -314 1.287
OPCl Phosphorus oxychloride 2 A' 308 495 187 0.622
OPCl Phosphorus oxychloride 3 A' 492 304 -188 1.619
H2OH2O water dimer 12 A" 88 -61 -149 -1.444
CHFCl Chlorofluoromethyl radical 6 A 540 405 -135 1.333
NH2NN+ hydrazoic acid, protonated 6 A' 489 407 -82 1.201
H2CNCN cyanamide, methylene 3 A' 2208 3093 885 0.714
H2CNCN cyanamide, methylene 4 A' 1621 2298 677 0.705
C2H3NO Nitrosoethylene 11 A' 490 348 -142 1.410
SNO Nitrogen oxide sulfide 3 A' 792 505 -287 1.569
ONNO NO dimer 2 A1 239 416 177 0.575
ONNO NO dimer 3 A1 135 350 215 0.384
ONNO NO dimer 4 torsion A2 117 196 79 0.598
ONNO NO dimer 6 B2 429 768 339 0.559
AlNC Aluminum isocyanide 3 Π 100 153 53 0.655
ClONO chlorine nitrite 4 A' 406 582 176 0.697