return to home page

XIII.F.2. (III.B.7.b.) (IV.C.7.) (XVIII.B.2.)

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 MP2/6-311G**
Calculated values were scaled by 0.9502.

Species Name mode Symmetry Experiment Theory difference ratio
CH3COOH Acetic acid 18 A" 93 71 -22 1.307
CH3OH Methyl alcohol 12 A" 200 331 131 0.605
CH3OH Methyl alcohol 12 A" 200 331 131 0.605
CH3OH Methyl alcohol 12 A" 200 331 131 0.605
CH3OH Methyl alcohol 12 A" 200 331 131 0.605
CH3CONH2 Acetamide 20 A 259 383 124 0.676
C2H6O2S Dimethyl sulfone 20 B1 262 214 -48 1.224
C6H6 Benzene 8 B2g 703 374 -329 1.881
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 332 118 0.645
HCN+ hydrogen cyanide cation 1 Σ 3050 3679 629 0.829
HCN+ hydrogen cyanide cation 2 Σ 1800 2759 959 0.652
CBr2F2 Methane, dibromodifluoro- 3 A1 140 330 190 0.425
C3F8 perfluoropropane 13 A2 276 220 -56 1.254
CHOCH(CH3)CH3 Propanal, 2-methyl- 16 A' 632 523 -109 1.209
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 55 -20 1.368
CH3COOCH3 methyl acetate 27 A" 110 37 -73 2.939
C9H8 Indene 40 A" 690 494 -196 1.398
C9H8 Indene 41 A" 549 366 -182 1.498
C9H8 Indene 43 A" 388 317 -70 1.222
C6H5CN phenyl cyanide 19 B1 688 524 -164 1.313
C6H5CN phenyl cyanide 20 B1 542 428 -114 1.265
C6H5CHO benzaldehyde 32 A" 688 409 -279 1.684
C6H4O2 parabenzoquinone 16 B2g 794 654 -140 1.215
C6H4O2 parabenzoquinone 17 B2g 241 143 -98 1.686
C6H4O2 parabenzoquinone 30 B3u 109 81 -27 1.335
C3H6O 2-Propen-1-ol 24 A 188 111 -77 1.687
C6H5Cl chlorobenzene 18 B1 685 419 -265 1.632
C6H5Cl chlorobenzene 19 B1 467 347 -120 1.345
C5H12 Pentane 23 A2 131 91 -40 1.445
C3H2N2 Malononitrile 6 A1 167 136 -31 1.227
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 A2 193 146 -47 1.322
C4H8O2 1,4-Dioxane 19 Au 288 235 -53 1.224
C5H8 Cyclopentene 18 A' 254 181 -73 1.407
C4H4N2 Pyridazine 13 A2 421 332 -89 1.269
NH2CN cyanamide 5 A' 408 681 273 0.599
C6H5F Fluorobenzene 18 B1 685 499 -186 1.373
C6H5F Fluorobenzene 19 B1 500 407 -93 1.230
C4H2 Diacetylene 7 Πg 482 205 -277 2.356
C4H6O2 2,3-Butanedione 9 Ag 614 507 -107 1.212
C4H6O2 2,3-Butanedione 13 Au 1111 920 -191 1.207
C4H6O2 2,3-Butanedione 21 Bg 240 120 -120 2.006
CH3CCCH3 2-Butyne 16 E" 371 258 -113 1.436
C3O2 Carbon suboxide 7 Πu 61 35 -26 1.731
C6H4F2 1,4-difluorobenzene 16 B2g 692 521 -171 1.329
C5H8 1,4-Pentadiene 16 A 137 289 152 0.473
C5H8 1,4-Pentadiene 17 A 102 83 -19 1.234
C6H10 1,5-Hexadiene 14 Ag 351 261 -90 1.346
C6H10 1,5-Hexadiene 20 Au 649 537 -112 1.208
C6H10 1,5-Hexadiene 29 Bg 264 155 -109 1.705
COBr2 Carbonic dibromide 4 B1 757 498 -259 1.521
COBr2 Carbonic dibromide 6 B2 512 336 -176 1.522
CO+ carbon monoxide cation 1 Σ 2214 2738 524 0.809
CO+ carbon monoxide cation 1 Σ 2214 2738 524 0.809
CO+ carbon monoxide cation 1 Σ 2214 2738 524 0.809
CO+ carbon monoxide cation 1 Σ 2214 2738 524 0.809
CH2D2 methane-d2 6 B1 3013 2261 -752 1.333
CH2D2 methane-d2 8 B2 2234 3053 819 0.732
C6H8 1,4-Cyclohexadiene 19 B1u 108 64 -44 1.696
C6H8 1,4-Cyclohexadiene 23 B2g 403 307 -96 1.311
C6H8 1,3,5-Hexatriene, (E)- 36 Bu 170 138 -32 1.232
C4H6 Cyclobutene 13 A2 325 261 -64 1.246
CaO Calcium monoxide 1 Σ 732 506 -226 1.446
ZnS Zinc sulfide 1 Σ 459 368 -91 1.247
NaOH sodium hydroxide 3 Π 300 210 -90 1.426
C4N2 2-Butynedinitrile 3 Σg 692 571 -121 1.212
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 212 68 0.679
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 321 -135 1.422
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 111 -60 1.534
CN Cyano radical 1 Σ 2069 2715 646 0.762
CH3OO methylperoxy radical 12 A" 170 137 -33 1.240
C2H Ethynyl radical 2 Σ 1841 2348 507 0.784
C2H Ethynyl radical 3 Π 372 796 424 0.467
CH3 Methyl radical 2 A2" 606 397 -209 1.528
CH3 Methyl radical 2 A2" 606 397 -209 1.528
CH3 Methyl radical 2 A2" 606 397 -209 1.528
CH3 Methyl radical 2 A2" 606 397 -209 1.528
CH2OH Hydroxymethyl radical 8 A 482 698 216 0.690
CH2OH Hydroxymethyl radical 9 A 234 443 209 0.528
C6H8 1,3,5-Hexatriene, (Z)- 11 A1 1136 855 -281 1.329
C6H8 1,3,5-Hexatriene, (Z)- 19 A2 264 117 -147 2.248
C6H8 1,3,5-Hexatriene, (Z)- 24 B1 358 88 -270 4.067
C4H6 Methylenecyclopropane 17 B1 360 259 -101 1.392
CH2CHO Vinyloxy radical 10 A" 703 1019 316 0.690
O2+ diatomic oxygen cation 1 Σg 1906 1407 -499 1.354
O2+ diatomic oxygen cation 1 Σg 1906 1407 -499 1.354
O2+ diatomic oxygen cation 1 Σg 1906 1407 -499 1.354
O2+ diatomic oxygen cation 1 Σg 1906 1407 -499 1.354
C2Cl2+ dichloroacetylene cation 5 Πu 233 177 -56 1.315
BF3+ boron trifluoride cation 3 E' 1662 2147 485 0.774
MgF2 Magnesium fluoride 3 Πu 165 135 -30 1.221
FOOF Perfluoroperoxide 3 A 360 233 -127 1.547
FOOF Perfluoroperoxide 4 A 202 127 -75 1.586
ZnCl Zinc monochloride 1 Σ 391 300 -90 1.300
CaF2 Calcium difluoride 2 A1 120 60 -60 1.994
O3 Ozone 3 B2 1042 2168 1126 0.481
NO Nitric oxide 1 Σ 1904 3381 1477 0.563
NO2 Nitrogen dioxide 3 B2 1618 2326 708 0.696
Li2O dilithium oxide 3 Πu 112 61 -50 1.825
FO Oxygen monofluoride 1 Σ 1053 2331 1278 0.452
FO Oxygen monofluoride 1 Σ 1053 2331 1278 0.452
PCl5 Phosphorus pentachloride 2 A1' 370 266 -104 1.393
N2O4 Dinitrogen tetroxide 9 B2u 265 196 -69 1.352
PS phosphorus sulfide 1 Σ 739 1284 545 0.575
C3 carbon trimer 3 Πu 63 163 100 0.388
C3 carbon trimer 3 Πu 63 163 100 0.388
N2O3 Dinitrogen trioxide 9 A" 63 164 101 0.384
C3 carbon trimer 3 Πu 63 163 100 0.388
C3 carbon trimer 3 Πu 63 163 100 0.388
C5H5- cylopentadienyl anion 14 E2" 600 478 -122 1.254
CaOH Calcium monohydroxide 2 Σ 353 622 269 0.568
CaOH Calcium monohydroxide 3 Π 609 349 -260 1.744
C5H5- cylopentadienyl anion 8 E1" 625 497 -128 1.257
ClNO2 Nitryl chloride 3 A1 364 278 -86 1.309
AlO Aluminum monoxide 1 Σ 979 745 -234 1.314
SiH- silicon monohydride anion 1 Σ 2175 1812 -363 1.200
FO2 Dioxygen monofluoride 2 A' 579 68 -512 8.542
FO2 Dioxygen monofluoride 3 A' 376 28 -348 13.302
SiH- silicon monohydride anion 1 Σ 2175 1812 -363 1.200
SF5Cl sulfur chloropentafluoride 5 B1 625 457 -168 1.368
SF5Cl sulfur chloropentafluoride 7 B2 505 309 -196 1.636
SF5Cl sulfur chloropentafluoride 11 E 397 243 -154 1.632
ClOO chloroperoxy radical 2 A' 414 1057 644 0.391
ClOO chloroperoxy radical 3 A' 201 488 287 0.413
PO Phosphorus monoxide 1 Σ 1233 3579 2346 0.345
PO Phosphorus monoxide 1 Σ 1233 3579 2346 0.345
PO Phosphorus monoxide 1 Σ 1233 3579 2346 0.345
PO Phosphorus monoxide 1 Σ 1233 3579 2346 0.345
GeH2 germylene 1 A1 1856 941 -915 1.972
HOClO Chlorous acid 4 A 592 492 -100 1.203
AsN Arsenic mononitride 1 Σ 1069 818 -251 1.306
SCN thiocyanato radical 1 Σ 1942 2414 472 0.805
ZnCH3 Zinc monomethyl 6 E 315 597 282 0.527
NCO isocyanato radical 1 Σ 1921 2358 437 0.815
F3- trifluoride anion 1 Σg 461 378 -83 1.220
H2POH Phosphinous acid 9 A" 375 262 -113 1.432
Mg2 Magnesium diatomic 1 Σg 51 27 -24 1.901
Mg2 Magnesium diatomic 1 Σg 51 27 -24 1.901
Mg2 Magnesium diatomic 1 Σg 51 27 -24 1.901
Mg2 Magnesium diatomic 1 Σg 51 27 -24 1.901
ONONO Nitrosyl nitrite 9 B2 380 219 -161 1.733