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/cc-pVTZ
Calculated values were scaled by 0.9495.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 167 54 0.676
CH3CONH2 Acetamide 20 A 259 204 -55 1.271
CH3OH Methyl alcohol 12 A" 200 293 93 0.682
CH3COCH3 Acetone 12 A2 77 -14 -91 -5.420
C2H4+ Ethylene cation 4 Au 84 -136 -220 -0.619
HCN+ hydrogen cyanide cation 1 Σ 3050 3571 521 0.854
HCN+ hydrogen cyanide cation 2 Σ 1800 2717 917 0.663
CHONH2 formamide 12 A" 289 79 -210 3.663
C3F8 perfluoropropane 13 A2 276 217 -59 1.271
CH3COCH2CH3 2-Butanone 33 A" 87 -20 -107 -4.324
CH3COOCH3 methyl acetate 27 A" 110 44 -66 2.489
C6H4O2 parabenzoquinone 30 B3u 109 85 -23 1.273
C3H6O 2-Propen-1-ol 24 A 188 107 -81 1.757
C4H8S Thiophene, tetrahydro- 5 A 1464 2943 1479 0.498
C4H8S Thiophene, tetrahydro- 6 A 1441 2943 1502 0.490
C4H8S Thiophene, tetrahydro- 7 A 1321 2928 1607 0.451
C4H8S Thiophene, tetrahydro- 8 A 1276 2927 1651 0.436
C4H8S Thiophene, tetrahydro- 12 A 888 1413 525 0.629
C4H8S Thiophene, tetrahydro- 13 A 829 1293 464 0.641
C4H8S Thiophene, tetrahydro- 14 A 822 1270 448 0.647
C4H8S Thiophene, tetrahydro- 15 A 678 1244 566 0.545
C4H8S Thiophene, tetrahydro- 16 A 472 1229 757 0.384
C4H8S Thiophene, tetrahydro- 17 A 290 1187 897 0.244
C5H8 Cyclopentene 18 A' 254 172 -82 1.478
CH2NN diazomethane 6 B1 406 122 -284 3.326
NH2CN cyanamide 5 A' 408 635 227 0.642
C4H6O2 2,3-Butanedione 21 Bg 240 115 -125 2.090
C2H3NO3 Oxamic acid 3 A' 2600 3444 844 0.755
C2H3NO3 Oxamic acid 15 A' 328 258 -70 1.273
C2H3NO3 Oxamic acid 17 A" 815 642 -173 1.269
C2H3NO3 Oxamic acid 21 A" 162 60 -102 2.696
C3H6O Oxetane 18 B1 90 -68 -158 -1.314
HCNO fulminic acid 5 Π 224 -330 -554 -0.679
C5H8 1,4-Pentadiene 16 A 137 288 151 0.476
CO+ carbon monoxide cation 1 Σ 2214 2729 515 0.811
C6H6 Benzvalene 10 A1 996 731 -265 1.362
H2CS- thioformaldehyde anion 4 B1 450 201 -249 2.235
NaOH sodium hydroxide 3 Π 300 212 -88 1.415
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 212 68 0.680
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 338 -118 1.350
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 124 -47 1.382
CN Cyano radical 1 Σ 2069 2749 681 0.752
C2H Ethynyl radical 2 Σ 1841 2392 551 0.769
C2H Ethynyl radical 3 Π 372 779 407 0.477
CH3OO methylperoxy radical 12 A" 170 123 -47 1.383
CH3 Methyl radical 2 A2" 606 457 -149 1.326
CH2OH Hydroxymethyl radical 9 A 234 417 183 0.561
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 857 -279 1.325
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 140 -124 1.880
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 96 -262 3.717
HCCN cyanomethylene 5 Π 129 -475 -604 -0.271
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.644
C4H6 Methylenecyclopropane 17 B1 360 267 -93 1.347
O2+ diatomic oxygen cation 1 Σg 1906 1416 -490 1.346
O3 Ozone 3 B2 1042 2128 1086 0.490
NO Nitric oxide 1 Σ 1904 3170 1265 0.601
NO2 Nitrogen dioxide 3 B2 1618 4049 2431 0.400
N2O4 Dinitrogen tetroxide 9 B2u 265 193 -72 1.372
N2O3 Dinitrogen trioxide 9 A" 63 160 97 0.395
C3O Tricarbon monoxide 5 Π 109 156 47 0.699
NO3 Nitrogen trioxide 3 E' 1492 2276 783 0.656
NO3 Nitrogen trioxide 4 E' 360 699 339 0.515
VO Vanadium monoxide 1 Σ 1011 2057 1046 0.492
C3 carbon trimer 3 Πu 63 164 100 0.388
SiP Silicon monophosphide 1 Σ 616 986 371 0.624
PS phosphorus sulfide 1 Σ 739 1542 803 0.479
SO+ sulfur monoxide cation 1 Σ 1360 3502 2142 0.388
AlO Aluminum monoxide 1 Σ 979 696 -284 1.408
FO2 Dioxygen monofluoride 1 A' 1487 2676 1189 0.556
FO2 Dioxygen monofluoride 2 A' 579 1243 664 0.466
FO2 Dioxygen monofluoride 3 A' 376 650 274 0.579
SCN thiocyanato radical 1 Σ 1942 2399 457 0.810
ClOO chloroperoxy radical 2 A' 414 1048 634 0.395
ClOO chloroperoxy radical 3 A' 201 475 274 0.424
OPCl Phosphorus oxychloride 2 A' 308 481 173 0.641
OPCl Phosphorus oxychloride 3 A' 492 289 -203 1.702
NCO isocyanato radical 1 Σ 1921 2350 429 0.818
H2POH Phosphinous acid 9 A" 375 261 -114 1.437
Mg2 Magnesium diatomic 1 Σg 51 40 -11 1.282
ClONO chlorine nitrite 4 A' 406 294 -112 1.381
ONONO Nitrosyl nitrite 9 B2 380 226 -154 1.679