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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 MP2/3-21G*
Calculated values were scaled by 0.9513.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C4H10O Ethoxy ethane 12 A1 240 175 -65 1.372
C4H10O Ethoxy ethane 20 A2 137 100 -37 1.364
C4H10O Ethoxy ethane 28 B1 126 91 -35 1.390
CH3OH Methyl alcohol 12 torsion A" 200 364 164 0.550
C2H4+ Ethylene cation 4 torsion Au 84 -253 -337 -0.333
C2H2 Acetylene 4 Πg 612 484 -128 1.265
HCN+ hydrogen cyanide cation 1 Σ 3050 3835 785 0.795
HCN+ hydrogen cyanide cation 2 Σ 1800 2838 1038 0.634
CH3CCH propyne 10 E 328 234 -94 1.399
CH2I2 Diiodomethane 3 A1 704 474 -230 1.485
CH2I2 Diiodomethane 4 A1 285 112 -173 2.545
CH2I2 Diiodomethane 9 B2 738 575 -163 1.283
C3F8 perfluoropropane 13 A2 276 202 -74 1.368
CH3COCH2CH3 2-Butanone 33 torsion A" 87 67 -20 1.290
CH3COOCH3 methyl acetate 26 torsion A" 136 97 -39 1.398
CH3COOCH3 methyl acetate 27 torsion A" 110 86 -24 1.275
C10H8 naphthalene 27 B2g 770 527 -243 1.461
CH3CH2CH2CH3 Butane 5 Ag 1442 415 -1027 3.478
CH3CH2CH2CH3 Butane 7 Ag 1361 805 -556 1.692
CH3CH2CH2CH3 Butane 30 Bu 1461 2931 1470 0.498
CH3CH2CH2CH3 Butane 35 Bu 964 2999 2035 0.321
C3H6O 2-Propen-1-ol 24 A 188 94 -95 2.012
CH2ClCHO chloroacetaldehyde 15 torsion A 27 69 42 0.392
CH2ClCHO chloroacetaldehyde 15 A" 59 169 110 0.349
C2H2O2 Ethanedial 7 torsion Au 127 193 66 0.657
CH3OCHO methyl formate 18 torsion A" 130 87 -43 1.491
C3F6 hexafluoropropene 21 A" 60 -12 -72 -4.870
C4H8O2 1,4-Dioxane 19 Au 288 224 -64 1.286
CO2 Carbon dioxide 3 Πu 667 525 -142 1.271
C5H8 Cyclopentene 18 torsion A' 254 126 -128 2.021
CH2N4 1H-Tetrazole 11 A' 925 702 -223 1.318
C4H4N2 Pyridazine 8 A1 964 755 -209 1.277
C2H2N4 sym-tetrazine 3 Ag 1009 795 -214 1.270
C2H2N4 sym-tetrazine 13 B2u 883 666 -217 1.326
CH2NN diazomethane 6 B1 406 250 -156 1.625
C4H6O2 2,3-Butanedione 16 torsion Au 48 70 22 0.688
C4H6O2 2,3-Butanedione 21 torsion Bg 240 94 -146 2.565
C4H2 Diacetylene 7 Πg 482 -704 -1186 -0.685
C4H2 Diacetylene 8 Πu 630 496 -134 1.271
C4H2 Diacetylene 9 Πu 231 114 -117 2.027
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 978 -413 1.423
F2CCCF2 tetrafluoroallene 11 E 90 61 -29 1.471
C2H3NO3 Oxamic acid 3 A' 2600 3333 733 0.780
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.280
C2H3NO3 Oxamic acid 17 A" 815 636 -179 1.282
C2H3NO3 Oxamic acid 21 A" 162 110 -52 1.476
CH3CCCH3 2-Butyne 16 E" 371 191 -180 1.944
C3H6O Oxetane 7 A1 1018 802 -216 1.269
C3H6O Oxetane 18 B1 90 25 -65 3.553
C3H6O Oxetane 23 B2 1228 921 -307 1.334
Zn(CH3)2 dimethyl zinc 11 E' 134 -100 -234 -1.344
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 683 -2396 4.507
C5H8 1,4-Pentadiene 16 A 137 297 160 0.461
C5H8 1,4-Pentadiene 17 torsion A 102 80 -22 1.279
C5H8 1,4-Pentadiene 17 torsion A 102 80 -22 1.279
C2H4F2 1,2-difluoroethane 18 Bu 295 224 -71 1.315
CH3ONO Methyl nitrite 5 A' 1408 1116 -292 1.262
C6H8 1,4-Cyclohexadiene 19 B1u 108 62 -46 1.751
C6H6 Benzvalene 10 A1 996 786 -210 1.267
H2CS- thioformaldehyde anion 4 B1 450 135 -315 3.339
C4N2 2-Butynedinitrile 6 Πg 504 729 225 0.692
MgO magnesium oxide 1 Σ 775 1113 338 0.696
LiOH lithium hydroxide 3 Π 257 447 190 0.574
FCN Cyanogen fluoride 3 Π 451 355 -95 1.269
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 222 78 0.650
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 334 -122 1.365
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 110 -61 1.551
CCl2 dichloromethylene 3 B2 758 599 -159 1.266
CFCl2 dichlorofluoromethyl radical 2 A' 747 559 -188 1.336
FCO+ Carbonyl fluoride cation 3 Π 650 447 -203 1.455
CN Cyano radical 1 Σ 2042 2486 444 0.821
C2H Ethynyl radical 3 torsion Π 372 769 397 0.483
CH3 Methyl radical 2 torsion A2" 606 404 -203 1.502
CNN Diazocarbene 3 Π 396 292 -104 1.358
CH2OH Hydroxymethyl radical 8 torsion A 482 709 227 0.679
CH2OH Hydroxymethyl radical 9 torsion A 234 430 196 0.544
HCO Formyl radical 1 A' 2434 3030 595 0.804
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 843 -293 1.348
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 119 -145 2.217
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 85 -273 4.216
C6H8 (Z)-hexa-1,3,5-triene 36 B2 243 348 105 0.699
HCCN cyanomethylene 5 Π 129 -392 -521 -0.329
ClNO Nitrosyl chloride 1 A' 1800 1348 -452 1.335
H2CCCCH2 Butatriene 10 B2g 544 194 -350 2.801
H2CCCCH2 Butatriene 16 B3g 330 218 -112 1.511
HNCS Isothiocyanic acid 4 A' 615 467 -148 1.316
CH3SO2NH2 methanesulfonamide 11 A' 689 508 -181 1.357
C6H6 Trimethylenecycopropane 20 E" 340 255 -85 1.333
CHCl2 dichloromethyl radical 4 A' 190 299 109 0.635
CH2CHO Vinyloxy radical 10 A" 703 1023 320 0.687
CH2Cl chloromethyl radical 4 B1 402 -166 -568 -2.421
TeO2 Tellurium Dioxide 1 A1 823 222 -601 3.704
HClO4 perchloric acid 12 A" 191 114 -77 1.672
BF3+ boron trifluoride cation 5 B2 1791 3834 2043 0.467
SOCl2 thionyl chloride 6 A" 284 225 -59 1.263
H2O2 Hydrogen peroxide 4 torsion A 371 144 -227 2.568
N2 Nitrogen diatomic 1 Σg 2330 1757 -573 1.326
N2 Nitrogen diatomic 1 Σg 1733 1316 -418 1.318
O2 Oxygen diatomic 1 Σg 1556 918 -639 1.696
O2+ diatomic oxygen cation 1 Σg 1873 669 -1204 2.799
HNO2 Nitrous acid 2 A' 1700 1251 -448 1.358
HN3 hydrogen azide 4 A' 1151 882 -268 1.304
HN3+ Hydrazoic acid cation 2 A' 1850 2924 1074 0.633
HN3+ Hydrazoic acid cation 4 A' 850 518 -332 1.640
FOOF Perfluoroperoxide 1 A 1210 875 -335 1.383
FOOF Perfluoroperoxide 4 torsion A 202 134 -68 1.505
FOOF Perfluoroperoxide 5 B 614 886 272 0.693
NF3 Nitrogen trifluoride 4 E 492 385 -107 1.277
BeBr2 Beryllium bromide 3 Πu 207 330 123 0.628
BeF2 Beryllium fluoride 3 Πu 343 256 -86 1.337
FNO Nitrosyl fluoride 1 A' 1844 1208 -636 1.527
FNO3 Fluorine nitrate 9 torsion A" 152 113 -39 1.344
CaBr2 Calcium dibromide 3 Πu 72 118 46 0.610
HOCl+ hypochlorous acid cation 3 A' 830 1285 455 0.646
N2O Nitrous oxide 2 Σ 1285 977 -308 1.315
N2O Nitrous oxide 3 Π 589 459 -130 1.282
O3 Ozone 3 B2 1042 2964 1922 0.352
NO Nitric oxide 1 Σ 1876 4226 2350 0.444
NO+ nitric oxide cation 1 Σ 2344 1437 -907 1.631
NO2 Nitrogen dioxide 3 B2 1618 3042 1424 0.532
NO2+ Nitrogen dioxide cation 1 Σg 1397 1003 -393 1.392
NO2+ Nitrogen dioxide cation 3 Πu 639 471 -168 1.357
N2O4 Dinitrogen tetroxide 5 B1u 1261 992 -269 1.272
N2O4 Dinitrogen tetroxide 9 B2u 265 123 -142 2.150
N2O3 Dinitrogen trioxide 2 A' 1652 1230 -422 1.343
N2O3 Dinitrogen trioxide 3 A' 1305 1031 -274 1.266
N2O3 Dinitrogen trioxide 7 A' 205 106 -99 1.937
N2O3 Dinitrogen trioxide 9 torsion A" 63 188 125 0.336
VO Vanadium monoxide 1 Σ 1002 2134 1133 0.469
Li2O dilithium oxide 3 Πu 112 75 -36 1.480
FO Oxygen monofluoride 1 Σ 1033 1753 720 0.589
C3 carbon trimer 3 Πu 63 -132 -196 -0.479
LiO2 Lithium dioxide 3 B2 509 787 278 0.646
TiO Titanium monoxide 1 Σ 1000 1861 861 0.537
PO2 Phosphorus dioxide 3 B2 1328 2428 1101 0.547
CaOH Calcium monohydroxide 3 Π 353 505 152 0.699
C4 Carbon tetramer 4 Πg 323 -251 -574 -1.287
C4 Carbon tetramer 5 Πu 160 87 -73 1.842
BrNO Nitrosyl bromide 1 A' 1799 1274 -526 1.413
ClNO2 Nitryl chloride 1 A1 1267 990 -277 1.280
ClNO2 Nitryl chloride 3 A1 364 261 -103 1.393
NH2- amino anion 3 B2 3190 2646 -545 1.206
N2F2 Dinitrogen difluoride, (E)- 1 Ag 1523 919 -604 1.658
SiH2D2 silane-d2 6 B1 2183 1621 -562 1.346
SiH2D2 silane-d2 8 B2 1601 2243 642 0.714
SO Sulfur monoxide 1 Σ 1054 824 -230 1.279
HOClO Chlorous acid 4 A 592 465 -126 1.272
H3O+ hydronium cation 2 A1 954 340 -614 2.806
HNO Nitrosyl hydride 3 A' 1501 997 -504 1.505
ClONO2 Chlorine nitrate 2 A' 1293 1017 -275 1.271
FOO Dioxygen monofluoride radical 1 A' 1487 5785 4298 0.257
FOO Dioxygen monofluoride radical 2 A' 579 1131 552 0.512
N2H2 (E)-diazene 3 Ag 1529 1089 -440 1.404
SCN thiocyanato radical 1 Σ 1942 2605 663 0.746
ClOO chloroperoxy radical 1 A' 1443 3261 1818 0.443
ClOO chloroperoxy radical 2 A' 414 1041 627 0.398
ClOO chloroperoxy radical 3 A' 201 404 203 0.499
PN Phosphorus mononitride 1 Σ 1323 1048 -275 1.262
B4H10 Tetraborane(10) 11 A1 785 562 -223 1.397
B4H10 Tetraborane(10) 12 A1 559 252 -307 2.221
B4H10 Tetraborane(10) 19 A2 662 430 -232 1.540
B4H10 Tetraborane(10) 36 B2 236 363 127 0.650
AlCN Aluminum monocyanide 3 Π 132 268 136 0.492
B5H9 pentaborane9 13 B1 240 624 384 0.385
B5H9 pentaborane9 16 B2 1036 771 -265 1.344
B5H9 pentaborane9 18 B2 600 441 -159 1.361
B5H9 pentaborane9 22 E 1409 1093 -316 1.289
OPCl Phosphorus oxychloride 2 A' 308 463 155 0.665
OPCl Phosphorus oxychloride 3 A' 492 288 -204 1.707
S2N2 Disulfur dinitride 1 Ag 913 621 -292 1.471
S2N2 Disulfur dinitride 2 Ag 632 485 -147 1.302
H2OH2O water dimer 6 A' 311 505 194 0.616
H2OH2O water dimer 7 A' 143 267 124 0.536
H2OH2O water dimer 8 A' 103 207 104 0.498
H2OH2O water dimer 10 A" 523 808 285 0.647
H2OH2O water dimer 11 A" 108 214 106 0.505
H2OH2O water dimer 12 A" 88 131 43 0.672
H2POH Phosphinous acid 9 A" 375 218 -157 1.720
AsN Arsenic mononitride 1 Σ 1058 706 -352 1.499
Mg2 Magnesium diatomic 1 Σg 48 21 -27 2.270
CHFCl Chlorofluoromethyl radical 6 A 540 371 -169 1.455
BrONO2 Bromine nitrate 2 A' 1288 1001 -287 1.287
BrONO2 Bromine nitrate 8 A" 728 576 -152 1.264
ZnCH3 Zinc monomethyl 6 E 315 608 293 0.518
NH2NN+ hydrazoic acid, protonated 6 A' 489 90 -399 5.441
H2CNCN cyanamide, methylene 3 A' 2208 2968 760 0.744
H2COO Dioxymethyl radical 6 A' 908 584 -324 1.554
NNS Nitrogen sulfide 1 Σ 2048 1404 -644 1.459
SNO Nitrogen oxide sulfide 3 A' 792 548 -244 1.446
ONNO NO dimer 1 A1 1868 1135 -733 1.645
ONNO NO dimer 2 A1 239 465 225 0.515
ONNO NO dimer 3 A1 135 359 224 0.375
ONNO NO dimer 4 torsion A2 117 279 162 0.419
ONNO NO dimer 5 B2 1789 1251 -538 1.430
INO Nitrosyl iodide 1 A' 1785 1306 -479 1.367
INO Nitrosyl iodide 2 A' 216 437 221 0.494
INO Nitrosyl iodide 3 A' 470 195 -275 2.414
SSCl2 Thiothionyl chloride 5 A" 377 281 -96 1.340
ClONO chlorine nitrite 1 A' 1715 1213 -502 1.414
BrONO Bromine nitrite 1 A' 1723 1215 -508 1.418
ONONO Nitrosyl nitrite 1 A1 1740 1157 -583 1.504
ONONO Nitrosyl nitrite 6 B1 140 109 -31 1.280
ONONO Nitrosyl nitrite 7 B2 1697 1114 -583 1.524
NSO sulfinyl amidogen 2 A' 1010 758 -252 1.333