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 CCD/6-31+G**
Calculated values were scaled by 0.9423.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 305 105 0.657
C2H4+ Ethylene cation 4 Au 84 148 63 0.570
C2H2 Acetylene 4 Πg 612 471 -141 1.298
HCN+ hydrogen cyanide cation 1 Σ 3050 3496 446 0.872
HCN+ hydrogen cyanide cation 2 Σ 1800 2708 908 0.665
CHONH2 formamide 12 A" 289 -166 -455 -1.734
C3F8 perfluoropropane 13 A2 276 217 -59 1.274
CH3COOCH3 methyl acetate 27 A" 110 57 -53 1.942
C9H8 Indene 40 A" 690 468 -223 1.476
C9H8 Indene 41 A" 549 413 -136 1.329
C6H4O2 parabenzoquinone 16 B2g 794 571 -223 1.391
C6H4O2 parabenzoquinone 17 B2g 241 94 -147 2.569
C6H4O2 parabenzoquinone 30 B3u 109 75 -33 1.446
C3H6O 2-Propen-1-ol 24 A 188 104 -84 1.801
C5H8 Cyclopentene 18 A' 254 163 -91 1.558
NH2CN cyanamide 5 A' 408 633 225 0.645
C4H6O2 2,3-Butanedione 21 Bg 240 111 -129 2.158
C6H5F Fluorobenzene 18 B1 685 479 -206 1.429
C3H6O Oxetane 18 B1 90 -73 -163 -1.227
C6H4F2 1,4-difluorobenzene 16 B2g 692 460 -232 1.503
C5H8 1,4-Pentadiene 16 A 137 284 147 0.483
HCCBr bromoacetylene 5 Π 295 427 132 0.691
HCCCl Chloroacetylene 5 Π 326 229 -97 1.423
C6H8 1,4-Cyclohexadiene 19 B1u 108 75 -33 1.450
C6H8 1,4-Cyclohexadiene 23 B2g 403 291 -112 1.383
C6H6 Benzvalene 10 A1 996 746 -250 1.335
H2CS- thioformaldehyde anion 4 B1 450 266 -184 1.695
CaO Calcium monoxide 1 Σ 732 559 -173 1.309
CN Cyano radical 1 Σ 2069 2503 434 0.826
C2H Ethynyl radical 3 Π 372 708 337 0.524
CH3 Methyl radical 2 A2" 606 454 -152 1.335
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 92 -79 1.867
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 319 -137 1.428
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.675
CH2OH Hydroxymethyl radical 9 A 234 412 178 0.568
HCCN cyanomethylene 5 Π 129 -501 -630 -0.257
CHCl2 dichloromethyl radical 4 A' 190 297 107 0.639
C6H6 Trimethylenecycopropane 20 E" 340 253 -87 1.342
C6H6 Trimethylenecycopropane 10 A2" 212 160 -52 1.324
FOOF Perfluoroperoxide 1 A 1210 949 -261 1.275
O3 Ozone 3 B2 1042 1644 602 0.634
NO Nitric oxide 1 Σ 1904 3050 1146 0.624
NO2 Nitrogen dioxide 1 A1 1318 2280 962 0.578
NO2 Nitrogen dioxide 2 A1 750 -315 -1065 -2.380
NO2 Nitrogen dioxide 3 B2 1618 8152 6534 0.198
N2O3 Dinitrogen trioxide 9 A" 63 122 59 0.517
VO Vanadium monoxide 1 Σ 1011 1883 871 0.537
Li2O dilithium oxide 3 Πu 112 84 -28 1.330
FO Oxygen monofluoride 1 Σ 1053 2383 1330 0.442
C3 carbon trimer 3 Πu 63 -83 -146 -0.767
PS phosphorus sulfide 1 Σ 739 1107 367 0.668
PO Phosphorus monoxide 1 Σ 1233 2251 1017 0.548
PN+ phosphorus nitride cation 1 Σ 1200 2110 910 0.569
Cl3- trichloride anion 2 Σu 327 185 -142 1.766
CaS Calcium sulfide 1 Σ 462 350 -112 1.321
OPCl Phosphorus oxychloride 2 A' 308 485 177 0.635
OPCl Phosphorus oxychloride 3 A' 492 300 -192 1.640
H2OH2O water dimer 8 A' 103 154 51 0.671
H2OH2O water dimer 11 A" 108 160 52 0.675
H2OH2O water dimer 12 A" 88 131 43 0.671
F3- trifluoride anion 2 Σu 550 169 -381 3.255
H2POH Phosphinous acid 9 A" 375 258 -117 1.454
Mg2 Magnesium diatomic 1 Σg 51 15 -36 3.398
ZnCH3 Zinc monomethyl 6 E 315 599 284 0.526