return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) Standard Reference Database 101 National Institute of Standards and Technology
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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 MP2/6-31G**
Calculated values were scaled by 0.9365.

Species Name mode Symmetry Experiment Theory difference ratio
CH3SeH Methane selenol 12 A" 145 215 70 0.673
CH3OH Methyl alcohol 12 A" 200 326 126 0.614
CH3COCH3 Acetone 12 A2 77 53 -24 1.455
C6H6 Benzene 8 B2g 703 468 -235 1.503
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 312 98 0.685
C2H4+ Ethylene cation 4 Au 84 -59 -143 -1.427
C2H2 Acetylene 4 Πg 612 416 -196 1.473
HCN+ hydrogen cyanide cation 1 Σ 3050 3727 678 0.818
HCN+ hydrogen cyanide cation 2 Σ 1800 2775 975 0.649
CH3CCH propyne 10 E 328 255 -73 1.285
CHONH2 formamide 12 A" 289 -84 -372 -3.454
C3F8 perfluoropropane 13 A2 276 210 -66 1.316
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 57 -18 1.306
CH3COCH2CH3 2-Butanone 33 A" 87 27 -60 3.164
CH3COOCH3 methyl acetate 27 A" 110 62 -48 1.767
C10H8 naphthalene 12 Au 581 432 -149 1.346
C10H8 naphthalene 27 B2g 770 406 -364 1.897
C10H8 naphthalene 28 B2g 461 -222 -683 -2.079
C9H8 Indene 40 A" 690 496 -194 1.391
C9H8 Indene 41 A" 549 418 -131 1.314
C6H5CN phenyl cyanide 19 B1 688 511 -177 1.346
C6H5CHO benzaldehyde 32 A" 688 462 -226 1.488
C6H4O2 parabenzoquinone 16 B2g 794 619 -175 1.282
C6H4O2 parabenzoquinone 17 B2g 241 159 -82 1.518
C6H4O2 parabenzoquinone 30 B3u 109 83 -25 1.304
C3H6O 2-Propen-1-ol 24 A 188 107 -81 1.760
C6H5Cl chlorobenzene 18 B1 685 450 -234 1.520
C4H8S Thiophene, tetrahydro- 5 A 1464 2953 1489 0.496
C4H8S Thiophene, tetrahydro- 6 A 1441 2953 1512 0.488
C4H8S Thiophene, tetrahydro- 7 A 1321 2937 1616 0.450
C4H8S Thiophene, tetrahydro- 8 A 1276 2937 1661 0.434
C4H8S Thiophene, tetrahydro- 11 A 1023 1440 417 0.710
C4H8S Thiophene, tetrahydro- 12 A 888 1438 550 0.618
C4H8S Thiophene, tetrahydro- 13 A 829 1318 489 0.629
C4H8S Thiophene, tetrahydro- 14 A 822 1294 472 0.635
C4H8S Thiophene, tetrahydro- 15 A 678 1276 598 0.532
C4H8S Thiophene, tetrahydro- 16 A 472 1248 776 0.378
C4H8S Thiophene, tetrahydro- 17 A 290 1203 913 0.241
C5H8 Cyclopentene 18 A' 254 173 -81 1.466
C6F6 hexafluorobenzene 7 B2g 719 194 -525 3.705
C6F6 hexafluorobenzene 8 B2g 205 -220 -425 -0.931
NH2CN cyanamide 5 A' 408 637 229 0.641
C4H6O2 2,3-Butanedione 21 Bg 240 111 -129 2.160
F2CCCF2 tetrafluoroallene 11 E 90 66 -24 1.371
C6H5F Fluorobenzene 18 B1 685 481 -204 1.425
C2H3NO3 Oxamic acid 3 A' 2600 3453 853 0.753
C2H3NO3 Oxamic acid 16 A" 984 751 -233 1.310
C2H3NO3 Oxamic acid 21 A" 162 53 -109 3.053
CH3CCCH3 2-Butyne 16 E" 371 214 -157 1.730
C3H6O Oxetane 18 B1 90 -88 -177 -1.025
C3O2 Carbon suboxide 7 Πu 61 100 39 0.611
HCNO fulminic acid 5 Π 224 -359 -583 -0.624
C5H8 1,4-Pentadiene 16 A 137 286 149 0.479
HCCCl Chloroacetylene 5 Π 326 182 -144 1.793
C6H8 1,4-Cyclohexadiene 19 B1u 108 75 -33 1.447
CO+ carbon monoxide cation 1 Σ 2214 2703 489 0.819
C6H6 Benzvalene 10 A1 996 739 -257 1.348
C2F2 difluoroacetylene 4 Πg 270 172 -98 1.566
H2CS- thioformaldehyde anion 4 B1 450 -185 -635 -2.437
NaOH sodium hydroxide 3 Π 300 111 -189 2.699
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 212 68 0.679
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 323 -133 1.411
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 108 -63 1.578
FCO+ Carbonyl fluoride cation 3 Π 650 505 -145 1.288
CN Cyano radical 1 Σ 2069 2681 612 0.772
C2H Ethynyl radical 2 Σ 1841 2327 486 0.791
C2H Ethynyl radical 3 Π 372 762 390 0.488
CH3OO methylperoxy radical 12 A" 170 123 -47 1.377
CH3 Methyl radical 2 A2" 606 366 -241 1.658
CH2OH Hydroxymethyl radical 8 A 482 736 254 0.655
CH2OH Hydroxymethyl radical 9 A 234 431 197 0.543
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 858 -278 1.324
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 120 -144 2.192
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 89 -269 4.027
HCCN cyanomethylene 5 Π 129 -547 -676 -0.236
CHCl2 dichloromethyl radical 4 A' 190 300 110 0.633
CH2CHO Vinyloxy radical 10 A" 703 1010 307 0.696
C4H6 Methylenecyclopropane 17 B1 360 259 -101 1.390
O2 Oxygen diatomic 1 Σg 1484 1132 -352 1.311
O2+ diatomic oxygen cation 1 Σg 1906 1257 -649 1.516
O3 Ozone 3 B2 1042 2228 1186 0.468
NO Nitric oxide 1 Σ 1904 3665 1761 0.520
NO2 Nitrogen dioxide 3 B2 1618 2127 509 0.761
N2O4 Dinitrogen tetroxide 9 B2u 265 180 -85 1.471
N2O3 Dinitrogen trioxide 9 A" 63 164 101 0.385
C3O Tricarbon monoxide 5 Π 109 166 57 0.658
VO Vanadium monoxide 1 Σ 1011 2078 1066 0.487
Li2O dilithium oxide 3 Πu 112 61 -50 1.824
FO Oxygen monofluoride 1 Σ 1053 2331 1278 0.452
C3 carbon trimer 3 Πu 63 165 101 0.385
Cu2 Copper dimer 1 Σg 265 380 115 0.697
PS phosphorus sulfide 1 Σ 739 1172 433 0.631
ZnH2 Zinc hydride 3 Πu 633 476 -156 1.328
PO Phosphorus monoxide 1 Σ 1233 3842 2609 0.321
AlO Aluminum monoxide 1 Σ 979 719 -260 1.362
FO2 Dioxygen monofluoride 1 A' 1487 2752 1265 0.540
FO2 Dioxygen monofluoride 2 A' 579 1172 592 0.494
FO2 Dioxygen monofluoride 3 A' 376 620 244 0.607
SCN thiocyanato radical 1 Σ 1942 2398 455 0.810
ClOO chloroperoxy radical 2 A' 414 1023 609 0.404
ClOO chloroperoxy radical 3 A' 201 465 264 0.433
OPCl Phosphorus oxychloride 2 A' 308 475 167 0.648
OPCl Phosphorus oxychloride 3 A' 492 284 -208 1.733
H2POH Phosphinous acid 9 A" 375 255 -121 1.474
AsN Arsenic mononitride 1 Σ 1069 818 -250 1.306
Mg2 Magnesium diatomic 1 Σg 51 318 267 0.161
ZnCH3 Zinc monomethyl 6 E 315 598 283 0.527
ZnCN Zinc monocyanide 3 Π 212 -36 -248 -5.809
ONONO Nitrosyl nitrite 9 B2 380 257 -123 1.478