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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 MP2=FULL/6-31G(2df,p)
Calculated values were scaled by 0.9399.

Species Name mode int rot Symmetry Experiment Theory difference ratio
CH3SeH Methane selenol 12 torsion A" 145 228 83 0.637
CH3CONH2 Acetamide 20 A 259 184 -74 1.404
CH3OH Methyl alcohol 12 torsion A" 200 318 118 0.629
C2H4+ Ethylene cation 4 torsion Au 84 -119 -203 -0.706
C2H2 Acetylene 4 Πg 612 472 -140 1.297
HCN+ hydrogen cyanide cation 1 Σ 3050 3522 472 0.866
HCN+ hydrogen cyanide cation 2 Σ 1800 2697 897 0.667
CHONH2 formamide 12 torsion A" 289 97 -191 2.963
C3F8 perfluoropropane 13 A2 276 213 -63 1.295
CH3CH2CH2CH3 Butane 5 Ag 1442 407 -1035 3.545
CH3CH2CH2CH3 Butane 8 Ag 1151 822 -329 1.399
CH3CH2CH2CH3 Butane 30 Bu 1461 2926 1465 0.499
CH3CH2CH2CH3 Butane 35 Bu 964 3014 2050 0.320
C3H6O 2-Propen-1-ol 24 A 188 107 -81 1.754
C3F6 hexafluoropropene 21 A" 60 39 -21 1.553
CH2NN diazomethane 6 B1 406 131 -275 3.101
NH2CN cyanamide 5 torsion A' 408 632 224 0.645
C4H6O2 2,3-Butanedione 21 torsion Bg 240 126 -114 1.901
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 1019 -372 1.365
C3H6O Oxetane 18 B1 90 -76 -166 -1.176
C3O2 Carbon suboxide 7 Πu 61 92 31 0.662
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 669 -2409 4.599
CO+ carbon monoxide cation 1 Σ 2184 2685 501 0.813
C6H6 Benzvalene 10 A1 996 736 -260 1.353
C2F2 difluoroacetylene 4 Πg 270 452 182 0.597
SiF2+ Silicon difluoride cation 2 A1 350 269 -81 1.303
CH2NH+ Methanimine cation 4 A' 1370 1788 418 0.766
CN Cyano radical 1 Σ 2042 2721 679 0.750
C2H Ethynyl radical 2 Σ 1841 2382 541 0.773
C2H Ethynyl radical 3 torsion Π 372 821 450 0.452
C2H+ Ethynyl cation 3 Π 550 808 258 0.680
CH3 Methyl radical 2 torsion A2" 606 372 -234 1.630
CH2OH Hydroxymethyl radical 8 torsion A 482 691 209 0.698
CH2OH Hydroxymethyl radical 9 torsion A 234 430 196 0.545
HCCN cyanomethylene 4 Π 383 549 166 0.697
HCCN cyanomethylene 5 Π 129 -315 -444 -0.410
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.644
CH2CHO Vinyloxy radical 10 A" 703 1026 323 0.685
HNC+ hydrogen isocyanide cation 2 Σ 2195 2652 457 0.828
CH2Cl chloromethyl radical 4 B1 402 -228 -630 -1.761
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.682
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 342 -114 1.333
H2CS- thioformaldehyde anion 4 B1 450 -155 -605 -2.911
CH2ClCHO chloroacetaldehyde 15 A" 59 172 113 0.343
CH2ClCHO chloroacetaldehyde 15 torsion A 27 58 31 0.465
C2Cl6 hexachloroethane 4 A1u 61 87 26 0.697
BF3+ boron trifluoride cation 5 B2 1791 3934 2143 0.455
O2+ diatomic oxygen cation 1 Σg 1873 1419 -454 1.320
HN3+ Hydrazoic acid cation 2 A' 1850 3061 1211 0.604
GaF3 Gallium trifluoride 4 E' 192 93 -99 2.067
BeBr2 Beryllium bromide 3 Πu 207 337 130 0.615
CaF2 Calcium difluoride 2 A1 120 84 -36 1.432
O3 Ozone 3 B2 1042 2070 1028 0.503
NO Nitric oxide 1 Σ 1876 3185 1309 0.589
NO2 Nitrogen dioxide 3 B2 1618 4509 2891 0.359
N2O3 Dinitrogen trioxide 9 torsion A" 63 169 106 0.373
C3O Tricarbon monoxide 5 Π 109 164 55 0.665
AsSe Arsenic monoselenide 1 Σ 280 480 200 0.583
NaO2 Sodium superoxide 3 B2 333 655 322 0.508
VO Vanadium monoxide 1 Σ 1002 1910 908 0.524
C3 carbon trimer 3 Πu 63 217 154 0.292
LiO2 Lithium dioxide 3 B2 509 890 381 0.572
SiP Silicon monophosphide 1 Σ 611 1009 398 0.606
SiH2D2 silane-d2 6 B1 2183 1586 -597 1.376
SiH2D2 silane-d2 8 B2 1601 2195 594 0.729
B4H10 Tetraborane(10) 11 A1 785 582 -203 1.348
B4H10 Tetraborane(10) 12 A1 559 237 -322 2.360
B4H10 Tetraborane(10) 19 A2 662 394 -268 1.679
B4H10 Tetraborane(10) 36 B2 236 345 109 0.684
B5H9 pentaborane9 13 B1 240 575 335 0.417
B5H9 pentaborane9 16 B2 1036 777 -259 1.333
B5H9 pentaborane9 22 E 1409 1043 -366 1.350
OPCl Phosphorus oxychloride 2 A' 308 486 178 0.634
OPCl Phosphorus oxychloride 3 A' 492 288 -204 1.710
H2OH2O water dimer 12 A" 88 50 -38 1.760
H2POH Phosphinous acid 9 A" 375 264 -112 1.423
ZnCH3 Zinc monomethyl 6 E 315 596 281 0.528
SNO Nitrogen oxide sulfide 3 A' 792 505 -287 1.569
ONONO Nitrosyl nitrite 9 B2 380 297 -83 1.278
NSO sulfinyl amidogen 3 A' 300 186 -114 1.610
ONNO NO dimer 2 A1 239 361 122 0.662
ONNO NO dimer 3 A1 135 335 201 0.401
ONNO NO dimer 4 torsion A2 117 279 162 0.420
H2CNCN cyanamide, methylene 3 A' 2208 2964 756 0.745
H2CNCN cyanamide, methylene 4 A' 1621 2083 462 0.778
CHFCl Chlorofluoromethyl radical 6 A 540 392 -148 1.376
NCO isocyanato radical 1 Σ 1921 2335 414 0.823