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 HF/CEP-31G*
Calculated values were scaled by 0.898.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 168 55 0.671
CH3OH Methyl alcohol 12 A" 200 307 107 0.652
CH3OH Methyl alcohol 12 A" 200 307 107 0.651
CH3OH Methyl alcohol 12 A" 200 307 107 0.652
CH3OH Methyl alcohol 12 A" 200 307 107 0.651
CH3COCH3 Acetone 12 A2 77 58 -19 1.337
C2H6O2S Dimethyl sulfone 20 B1 262 201 -61 1.303
CH3COCl Acetyl Chloride 15 A" 166 138 -28 1.200
CH3NO2 Methane, nitro- 11 A" 1583 3045 1462 0.520
C3F8 perfluoropropane 13 A2 276 220 -56 1.256
CHOCH(CH3)CH3 Propanal, 2-methyl- 16 A' 632 514 -118 1.229
CH3COOCH3 methyl acetate 27 A" 110 77 -33 1.428
C6H4O2 parabenzoquinone 30 B3u 109 90 -19 1.209
C3H6O 2-Propen-1-ol 24 A 188 106 -82 1.772
C5H12 Pentane 23 A2 131 102 -29 1.278
C4H8O Furan, tetrahydro- 17 A 286 233 -53 1.228
C4H8O2 1,4-Dioxane 19 Au 288 236 -52 1.219
C5H8 Cyclopentene 18 A' 254 177 -77 1.432
C5H8 Spiropentane 8 A2 919 731 -188 1.258
C2H3N3 1H-1,2,4-Triazole 18 A" 640 522 -118 1.226
C4H6O2 2,3-Butanedione 21 Bg 240 120 -120 1.993
C4H6O2 2,3-Butanedione 9 Ag 614 508 -106 1.208
C6H4 Benzyne 24 B2 472 82 -390 5.744
NH2CN cyanamide 5 A' 408 680 272 0.600
C3O2 Carbon suboxide 7 Πu 61 159 98 0.384
C2H3NO3 Oxamic acid 3 A' 2600 3451 851 0.753
C2H3NO3 Oxamic acid 15 A' 328 258 -70 1.274
C2H3NO3 Oxamic acid 17 A" 815 627 -188 1.299
C2H3NO3 Oxamic acid 18 A" 745 577 -168 1.292
C2H3NO3 Oxamic acid 20 A" 315 240 -75 1.313
C2H3NO3 Oxamic acid 21 A" 162 30 -132 5.451
C3H6O Oxetane 12 A2 986 795 -191 1.240
HCNO fulminic acid 5 Π 224 540 316 0.415
C5H8 1,4-Pentadiene 16 A 137 285 148 0.480
C5H8 1,4-Pentadiene 17 A 102 84 -18 1.209
C6H10 1,5-Hexadiene 14 Ag 351 252 -99 1.394
C6H10 1,5-Hexadiene 29 Bg 264 145 -119 1.818
CH3SSCH3 Disulfide, dimethyl 13 A 117 89 -28 1.316
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 188 -39 1.211
CH2D2 methane-d2 6 B1 3013 2196 -817 1.372
CH2D2 methane-d2 8 B2 2234 2965 731 0.754
C6H8 1,3,5-Hexatriene, (E)- 36 Bu 170 139 -31 1.227
C4N2 2-Butynedinitrile 3 Σg 692 568 -124 1.218
MgO magnesium oxide 1 Σ 785 650 -136 1.209
LiOH lithium hydroxide 3 Π 257 367 111 0.698
Si2H6 disilane 4 A1u 131 109 -22 1.203
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.683
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.684
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.683
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.684
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 346 -110 1.318
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 346 -110 1.319
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 346 -110 1.318
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 346 -110 1.319
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 124 -47 1.379
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 123 -48 1.386
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 124 -47 1.379
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 123 -48 1.386
CN Cyano radical 1 Σ 2069 1705 -363 1.213
C2H+ Ethynyl cation 3 Π 550 844 295 0.651
CH3 Methyl radical 2 A2" 606 288 -319 2.107
CH3 Methyl radical 2 A2" 606 288 -319 2.107
CH3 Methyl radical 2 A2" 606 288 -319 2.107
CH3 Methyl radical 2 A2" 606 288 -319 2.107
CH2OH Hydroxymethyl radical 8 A 482 783 301 0.616
CH2OH Hydroxymethyl radical 9 A 234 372 138 0.630
C2H5 Ethyl radical 9 A' 528 406 -123 1.302
C6H8 1,3,5-Hexatriene, (Z)- 24 B1 358 97 -261 3.674
C6H8 1,3,5-Hexatriene, (Z)- 11 A1 1136 848 -288 1.340
C6H8 1,3,5-Hexatriene, (Z)- 19 A2 264 142 -122 1.854
H2CCCCH2 Butatriene 16 B3g 330 197 -133 1.671
C3H3 Propargyl radical 6 B1 687 566 -121 1.214
C3H3 Propargyl radical 7 B1 490 372 -118 1.317
C2Cl2+ dichloroacetylene cation 5 Πu 233 187 -46 1.248
FOOF Perfluoroperoxide 2 A 630 1044 414 0.604
FOOF Perfluoroperoxide 5 B 614 1030 416 0.596
PCl5 Phosphorus pentachloride 2 A1' 370 277 -93 1.338
Li2O dilithium oxide 3 Πu 112 183 71 0.611
PS phosphorus sulfide 1 Σ 739 481 -258 1.538
N2O4 Dinitrogen tetroxide 3 Ag 265 408 143 0.649
N2O4 Dinitrogen tetroxide 4 Au 82 54 -28 1.520
S3- Sulfur trimer anion 3 B2 594 461 -133 1.290
N2O3 Dinitrogen trioxide 6 A' 241 413 172 0.584
N2O3 Dinitrogen trioxide 7 A' 205 326 121 0.628
N2O3 Dinitrogen trioxide 8 A" 414 608 194 0.681
N2O3 Dinitrogen trioxide 9 A" 63 96 33 0.654
NS Mononitrogen monosulfide 1 Σ 1219 789 -429 1.544
SiN Silicon nitride 1 Σ 1151 779 -372 1.478
C3 carbon trimer 3 Πu 63 260 197 0.244
C3 carbon trimer 3 Πu 63 260 197 0.244
C3 carbon trimer 3 Πu 63 260 197 0.244
C3 carbon trimer 3 Πu 63 260 197 0.244
CP Carbon monophosphide 1 Σ 1240 873 -367 1.421
HOClO Chlorous acid 3 A 978 755 -224 1.296
SiH- silicon monohydride anion 1 Σ 2175 1698 -477 1.281
SiH- silicon monohydride anion 1 Σ 2175 1698 -477 1.281
SiH- silicon monohydride anion 1 Σ 2175 1698 -477 1.281
SiH- silicon monohydride anion 1 Σ 2175 1698 -477 1.281
SF5Cl sulfur chloropentafluoride 5 B1 625 480 -145 1.303
SF5Cl sulfur chloropentafluoride 7 B2 505 331 -174 1.524
SF5Cl sulfur chloropentafluoride 11 E 397 258 -139 1.542
H3O+ hydronium 2 A1 954 787 -167 1.213
AlO Aluminum monoxide 1 Σ 979 698 -282 1.404
ClOO chloroperoxy radical 1 A' 1443 1089 -354 1.325
ClOO chloroperoxy radical 2 A' 414 644 231 0.642
ClOO chloroperoxy radical 3 A' 201 402 200 0.502
PN+ phosphorus nitride cation 1 Σ 1200 611 -589 1.962
ONONO Nitrosyl nitrite 9 B2 380 714 334 0.533
F3- trifluoride anion 2 Σu 550 -417 -967 -1.320
Mg2 Magnesium diatomic 1 Σg 51 2 -49 20.905
Cl3- trichloride anion 2 Σu 327 -82 -409 -3.979
NNS Nitrogen sulfide 2 Σ 752 537 -215 1.401
H2POH Phosphinous acid 9 A" 375 260 -116 1.446
ClS2 Sulfur chloride 1 A' 662 536 -126 1.235