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 mPW1PW91/6-31G*
Calculated values were scaled by 0.9483.

Species Name mode Symmetry Experiment Theory difference ratio
CH3COOH Acetic acid 18 A" 93 73 -20 1.277
CH3OH Methyl alcohol 12 A" 200 330 130 0.606
CH3OH Methyl alcohol 12 A" 200 329 129 0.608
CH3OH Methyl alcohol 12 A" 200 330 130 0.606
CH3OH Methyl alcohol 12 A" 200 329 129 0.608
CH3CONH2 Acetamide 20 A 259 137 -122 1.894
C3H4O2 β–Propiolactone 21 A" 113 174 61 0.648
CH3COCH3 Acetone 12 A2 77 21 -56 3.740
C2H6O2S Dimethyl sulfone 20 B1 262 209 -53 1.256
C2H6O2S Dimethyl sulfone 13 A2 326 269 -57 1.212
CHONH2 formamide 12 A" 289 144 -145 2.009
CH3COCl Acetyl Chloride 15 A" 166 132 -34 1.259
CH3NO2 Methane, nitro- 11 A" 1583 3061 1478 0.517
CBr2F2 Methane, dibromodifluoro- 3 A1 140 323 183 0.434
C3F8 perfluoropropane 13 A2 276 207 -69 1.335
C2F6 hexafluoroethane 4 A1u 68 47 -21 1.456
CH3COOCH3 methyl acetate 27 A" 110 50 -60 2.188
CHOCH(CH3)CH3 Propanal, 2-methyl- 16 A' 632 522 -110 1.211
C3H6O 2-Propen-1-ol 22 A 377 312 -65 1.209
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.681
C5H12 Pentane 23 A2 131 109 -22 1.207
C4H8O2 1,4-Dioxane 19 Au 288 239 -49 1.203
C5H8 Cyclopentene 18 A' 254 140 -114 1.818
C4H6O2 2,3-Butanedione 9 Ag 614 504 -110 1.218
C4H6O2 2,3-Butanedione 13 Au 1111 921 -190 1.207
C4H6O2 2,3-Butanedione 21 Bg 240 104 -136 2.302
C6H4 Benzyne 24 B2 472 377 -95 1.252
C3H6O Oxetane 12 A2 986 808 -178 1.221
C3H6O Oxetane 18 B1 90 51 -39 1.768
C5H12 Propane, 2,2-dimethyl- 12 T1 203 301 98 0.674
C2H3NO3 Oxamic acid 3 A' 2600 3451 851 0.753
C2H3NO3 Oxamic acid 15 A' 328 255 -73 1.284
C2H3NO3 Oxamic acid 16 A" 984 789 -195 1.247
C2H3NO3 Oxamic acid 17 A" 815 661 -154 1.233
C2H3NO3 Oxamic acid 18 A" 745 613 -132 1.215
C2H3NO3 Oxamic acid 21 A" 162 66 -96 2.438
C3O2 Carbon suboxide 7 Πu 61 114 53 0.537
C5H8 1,4-Pentadiene 16 A 137 283 146 0.484
C5H8 1,4-Pentadiene 17 A 102 83 -19 1.222
C6H10 1,5-Hexadiene 14 Ag 351 254 -97 1.382
C6H10 1,5-Hexadiene 29 Bg 264 184 -80 1.435
COBr2 Carbonic dibromide 6 B2 512 334 -178 1.533
COBr2 Carbonic dibromide 4 B1 757 504 -253 1.501
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 186 -41 1.219
CH3ONO Methyl nitrite 15 A" 186 116 -70 1.601
CH3SSCH3 Disulfide, dimethyl 13 A 117 96 -21 1.221
CH2D2 methane-d2 6 B1 3013 2248 -765 1.340
CH2D2 methane-d2 8 B2 2234 3036 802 0.736
C6H8 1,3,5-Hexatriene, (E)- 36 Bu 170 140 -30 1.218
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 208 64 0.693
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.694
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 208 64 0.693
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.694
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 342 -114 1.334
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.336
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 342 -114 1.334
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.336
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 141 -30 1.212
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 139 -32 1.227
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 141 -30 1.212
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 139 -32 1.227
C2H5 Ethyl radical 9 A' 528 435 -93 1.213
CH3OO methylperoxy radical 12 A" 170 134 -36 1.268
CH3 Methyl radical 2 A2" 606 433 -173 1.399
CH3 Methyl radical 2 A2" 606 433 -173 1.399
CH3 Methyl radical 2 A2" 606 433 -173 1.399
CH3 Methyl radical 2 A2" 606 433 -173 1.399
C6H8 1,3,5-Hexatriene, (Z)- 24 B1 358 99 -259 3.617
C6H8 1,3,5-Hexatriene, (Z)- 19 A2 264 147 -117 1.793
C6H8 1,3,5-Hexatriene, (Z)- 11 A1 1136 863 -273 1.316
CH2OH Hydroxymethyl radical 9 A 234 421 187 0.555
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.279
BF3+ boron trifluoride cation 4 E' 411 -193 -604 -2.130
BF3+ boron trifluoride cation 3 E' 1662 900 -761 1.846
C2Cl2+ dichloroacetylene cation 5 Πu 233 178 -55 1.311
MgF2 Magnesium fluoride 3 Πu 165 133 -32 1.244
SF4 Sulfur tetrafluoride 4 A1 228 185 -43 1.232
AsH3+ Arsine cation 2 A1 452 671 219 0.673
BrF5 bromine pentafluoride 6 B2 281 211 -70 1.329
ZnCN Zinc monocyanide 3 Π 212 67 -145 3.145
N2O3 Dinitrogen trioxide 9 A" 63 140 77 0.451
C3 carbon trimer 3 Πu 63 144 81 0.440
C3 carbon trimer 3 Πu 63 141 78 0.449
C3 carbon trimer 3 Πu 63 144 81 0.440
C3 carbon trimer 3 Πu 63 141 78 0.449
PCl5 Phosphorus pentachloride 2 A1' 370 269 -101 1.374
CaOH Calcium monohydroxide 3 Π 609 340 -269 1.792
CaOH Calcium monohydroxide 2 Σ 353 600 247 0.588
SiH- silicon monohydride anion 1 Σ 2175 1746 -429 1.245
SiH- silicon monohydride anion 1 Σ 2175 1746 -429 1.245
SiH- silicon monohydride anion 1 Σ 2175 1746 -429 1.245
SiH- silicon monohydride anion 1 Σ 2175 1746 -429 1.245
SF5Cl sulfur chloropentafluoride 5 B1 625 446 -179 1.401
SF5Cl sulfur chloropentafluoride 7 B2 505 302 -203 1.671
SF5Cl sulfur chloropentafluoride 11 E 397 238 -159 1.670
ZnH2 Zinc hydride 3 Πu 633 491 -142 1.289
ClOO chloroperoxy radical 2 A' 414 277 -136 1.492
ClOO chloroperoxy radical 3 A' 201 121 -81 1.671
Cl3- trichloride anion 2 Σu 327 266 -61 1.227
GeH2 germylene 1 A1 1856 904 -952 2.053
GeH2 germylene 2 A1 916 1752 836 0.523
H2POH Phosphinous acid 9 A" 375 252 -123 1.487
ZnCH3 Zinc monomethyl 6 E 315 592 277 0.532
H2OH2O water dimer 7 A' 143 222 79 0.645
H2OH2O water dimer 11 A" 108 165 57 0.655
H2OH2O water dimer 12 A" 88 50 -38 1.763
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597
Mg2 Magnesium diatomic 1 Σg 51 86 35 0.597