return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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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/aug-cc-pVTZ
Calculated values were scaled by 0.9529.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 165 52 0.686
C4H10O Ethoxy ethane 12 A1 240 185 -55 1.297
C4H10O Ethoxy ethane 20 A2 137 98 -39 1.394
CH3CONH2 Acetamide 20 A 259 171 -88 1.512
C2H4+ Ethylene cation 4 torsion Au 84 -244 -328 -0.345
HCN+ hydrogen cyanide cation 1 Σ 3050 3578 528 0.852
HCN+ hydrogen cyanide cation 2 Σ 1800 2721 921 0.662
CHONH2 formamide 12 torsion A" 289 128 -160 2.247
CH3COCH2CH3 2-Butanone 33 torsion A" 87 -18 -105 -4.961
CH3COOCH3 methyl acetate 27 torsion A" 110 46 -64 2.398
C6H4Cl2 1,4-dichlorobenzene 30 B3u 122 96 -26 1.270
CH3CH2CH2CH3 Butane 5 Ag 1442 407 -1035 3.544
CH3CH2CH2CH3 Butane 8 Ag 1151 818 -333 1.407
CH3CH2CH2CH3 Butane 30 Bu 1461 2919 1458 0.501
CH3CH2CH2CH3 Butane 36 Bu 271 3005 2734 0.090
C3H6O 2-Propen-1-ol 24 A 188 108 -80 1.744
CH2ClCHO chloroacetaldehyde 15 torsion A 27 53 26 0.508
C6H5Cl chlorobenzene 18 B1 685 542 -143 1.263
CHSNH2 thioformamide 12 A" 393 287 -106 1.371
C3F6 hexafluoropropene 21 A" 60 40 -20 1.497
C5H8 Cyclopentene 18 torsion A' 254 172 -82 1.477
CH2NN diazomethane 6 B1 406 81 -325 5.001
NH2CN cyanamide 5 torsion A' 408 619 211 0.659
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 1003 -388 1.386
F2CCCF2 tetrafluoroallene 11 E 90 68 -22 1.326
C6H5F Fluorobenzene 18 B1 685 531 -154 1.290
C3H6O Oxetane 18 B1 90 -92 -181 -0.979
C3O2 Carbon suboxide 7 Πu 61 -38 -99 -1.626
HCNO fulminic acid 5 torsion Π 224 -284 -508 -0.790
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 657 -2422 4.686
P(CH3)3 trimethylphosphine 22 E 259 200 -59 1.297
CO+ carbon monoxide cation 1 Σ 2184 2739 555 0.797
C6H6 Benzvalene 10 A1 996 730 -266 1.365
H2CS- thioformaldehyde anion 4 B1 450 292 -158 1.540
NaOH sodium hydroxide 3 torsion Π 300 213 -87 1.409
CH2NH+ Methanimine cation 4 A' 1370 1805 435 0.759
CN Cyano radical 1 Σ 2042 2760 717 0.740
C2H Ethynyl radical 2 Σ 1841 2400 560 0.767
C2H Ethynyl radical 3 torsion Π 372 782 410 0.475
C2H+ Ethynyl cation 3 Π 550 786 236 0.699
CH3 Methyl radical 2 torsion A2" 606 466 -140 1.302
CH2OH Hydroxymethyl radical 9 torsion A 234 415 181 0.564
HCCN cyanomethylene 5 Π 129 -482 -611 -0.267
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.642
C4H6 Methylenecyclopropane 17 B1 360 266 -94 1.355
CH2Cl chloromethyl radical 4 B1 402 -162 -564 -2.485
HNC+ hydrogen isocyanide cation 2 Σ 2195 2693 498 0.815
BF3+ boron trifluoride cation 5 B2 1791 3321 1530 0.539
O2+ diatomic oxygen cation 1 Σg 1873 1416 -457 1.323
HN3+ Hydrazoic acid cation 2 A' 1850 3155 1305 0.586
FOOF Perfluoroperoxide 3 A 360 261 -99 1.380
FOOF Perfluoroperoxide 4 torsion A 202 127 -75 1.587
O3 Ozone 3 B2 1042 2139 1097 0.487
NO Nitric oxide 1 Σ 1876 3178 1302 0.590
NO2 Nitrogen dioxide 3 B2 1618 4234 2616 0.382
N2O3 Dinitrogen trioxide 9 torsion A" 63 159 96 0.397
AsSe Arsenic monoselenide 1 Σ 280 410 130 0.683
GaO Gallium monoxide 1 Σ 755 577 -178 1.309
NaO2 Sodium superoxide 3 B2 333 805 473 0.413
VO Vanadium monoxide 1 Σ 1002 2080 1079 0.481
C3 carbon trimer 3 Πu 63 141 78 0.450
LiO2 Lithium dioxide 3 B2 509 958 449 0.531
MgOH magnesium hydroxide 3 torsion Π 188 69 -119 2.741
SiH2D2 silane-d2 6 B1 2183 1582 -601 1.380
SiH2D2 silane-d2 8 B2 1601 2189 588 0.731
AlO Aluminum monoxide 1 Σ 965 673 -292 1.434
GeF Germanium monofluoride 1 Σ 809 637 -172 1.271
BrO+ Bromine monoxide cation 1 Σ 840 1203 363 0.698
B4H10 Tetraborane(10) 10 A1 827 655 -172 1.262
B4H10 Tetraborane(10) 11 A1 785 570 -215 1.377
B4H10 Tetraborane(10) 12 A1 559 220 -339 2.539
B4H10 Tetraborane(10) 19 A2 662 401 -261 1.653
B4H10 Tetraborane(10) 36 B2 236 347 111 0.679
B5H9 pentaborane9 13 B1 240 587 347 0.409
B5H9 pentaborane9 16 B2 1036 774 -262 1.338
B5H9 pentaborane9 18 B2 600 468 -132 1.282
B5H9 pentaborane9 22 E 1409 1032 -377 1.365
OPCl Phosphorus oxychloride 2 A' 308 478 170 0.645
OPCl Phosphorus oxychloride 3 A' 492 287 -205 1.717
NCO isocyanato radical 1 Σ 1921 2357 435 0.815
H2POH Phosphinous acid 9 A" 375 256 -119 1.465
CHFCl Chlorofluoromethyl radical 6 A 540 394 -146 1.369
H2CNCN cyanamide, methylene 3 A' 2208 2971 763 0.743
H2CNCN cyanamide, methylene 4 A' 1621 2065 444 0.785
SNO Nitrogen oxide sulfide 3 A' 792 510 -282 1.552
ClONO chlorine nitrite 4 A' 406 297 -109 1.365
ONONO Nitrosyl nitrite 9 B2 380 83 -297 4.591