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 MP2/6-311G*
Calculated values were scaled by 0.9503.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 162 49 0.698
C4H10O Ethoxy ethane 12 A1 240 188 -52 1.275
C4H10O Ethoxy ethane 20 A2 137 85 -52 1.609
CH3CONH2 Acetamide 20 A 259 379 121 0.682
CH3COOH Acetic acid 18 torsion A" 93 71 -22 1.301
CH3OH Methyl alcohol 12 torsion A" 200 352 152 0.569
C2Cl6 hexachloroethane 4 A1u 61 91 30 0.671
C6H6 Benzene 8 B2g 703 379 -324 1.856
CH3CCl3 Ethane, 1,1,1-trichloro- 6 torsion A2 214 330 116 0.649
C2H4+ Ethylene cation 4 torsion Au 84 -79 -163 -1.069
C2H2 Acetylene 4 Πg 612 378 -234 1.620
HCN+ hydrogen cyanide cation 1 Σ 3050 3689 639 0.827
HCN+ hydrogen cyanide cation 2 Σ 1800 2758 958 0.653
CH3CCH propyne 10 E 328 227 -101 1.446
CH2I2 Diiodomethane 3 A1 704 474 -230 1.487
CH2I2 Diiodomethane 4 A1 285 116 -169 2.460
CH2I2 Diiodomethane 9 B2 738 573 -165 1.288
CHONH2 formamide 12 torsion A" 289 -220 -509 -1.311
CH3SCH3+ dimethyl sulfide cation 15 B1 172 132 -40 1.300
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 56 -19 1.331
CH3COCH2CH3 2-Butanone 33 torsion A" 87 -38 -125 -2.318
CH3COOCH3 methyl acetate 27 torsion A" 110 47 -63 2.355
C13H10 Fluorene 29 A2 566 343 -223 1.651
C13H10 Fluorene 30 A2 430 244 -186 1.759
C10H8 naphthalene 12 Au 581 365 -216 1.593
C10H8 naphthalene 27 B2g 770 398 -372 1.932
C10H8 naphthalene 28 B2g 461 -514 -975 -0.896
C9H8 Indene 40 A" 690 494 -196 1.397
C9H8 Indene 41 A" 549 371 -177 1.478
C6H5NO2 Nitrobenzene 22 B1 675 436 -239 1.547
C6H5CHCH2 Styrene 38 A" 633 392 -241 1.616
C6H5CHCH2 Styrene 40 A" 422 301 -121 1.404
C6H5CN phenyl cyanide 19 B1 688 527 -161 1.305
C6H5CHO benzaldehyde 32 A" 688 411 -277 1.673
C6H4Cl2 1,4-dichlorobenzene 16 B2g 687 349 -338 1.969
C6H4Cl2 1,4-dichlorobenzene 30 B3u 122 95 -27 1.289
C6H4O2 parabenzoquinone 17 B2g 241 160 -81 1.503
C6H4O2 parabenzoquinone 30 B3u 109 83 -25 1.306
C3H6O 2-Propen-1-ol 24 A 188 110 -78 1.714
CH2ClCHO chloroacetaldehyde 15 torsion A 27 57 30 0.473
C6H5Cl chlorobenzene 18 B1 685 422 -263 1.624
C6H5Cl chlorobenzene 19 B1 467 370 -97 1.264
C5H12 Pentane 23 A2 131 96 -35 1.360
CHSNH2 thioformamide 12 A" 393 141 -252 2.778
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 torsion A2 193 151 -42 1.279
C3F6 hexafluoropropene 21 A" 60 36 -24 1.673
C5H8 Cyclopentene 18 torsion A' 254 179 -75 1.423
CH2NN diazomethane 6 B1 406 -217 -623 -1.873
C6F6 hexafluorobenzene 7 B2g 719 318 -401 2.263
C6F6 hexafluorobenzene 8 B2g 205 111 -94 1.845
NH2CN cyanamide 5 torsion A' 408 669 261 0.610
C4H6O2 2,3-Butanedione 21 torsion Bg 240 119 -121 2.022
C4H2 Diacetylene 7 Πg 482 -328 -810 -1.471
C4H2 Diacetylene 8 Πu 630 445 -185 1.415
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 1017 -374 1.368
C6H5F Fluorobenzene 18 B1 685 507 -178 1.352
C2H3NO3 Oxamic acid 3 A' 2600 3478 878 0.748
C2H3NO3 Oxamic acid 20 A" 315 150 -165 2.095
C2H3NO3 Oxamic acid 21 A" 162 -61 -223 -2.661
CH3CCCH3 2-Butyne 16 E" 371 170 -201 2.182
C3H6O Oxetane 18 B1 90 -54 -143 -1.674
C3O2 Carbon suboxide 7 Πu 61 36 -25 1.697
HCNO fulminic acid 5 torsion Π 224 -359 -583 -0.624
C6H4Cl2 1,3-dichlorobenzene 18 B1 672 398 -274 1.689
CHBrCHBr Ethene, 1,2-dibromo-, (Z)- 8 B1 3079 652 -2427 4.724
C5H8 1,4-Pentadiene 16 A 137 293 156 0.468
C5H8 1,4-Pentadiene 33 torsion B 331 93 -238 3.544
HCCBr bromoacetylene 4 Π 618 487 -131 1.269
HCCBr bromoacetylene 5 Π 295 181 -114 1.632
HCCCl Chloroacetylene 5 Π 326 159 -167 2.054
P(CH3)3 trimethylphosphine 22 E 259 196 -63 1.324
C6H8 1,4-Cyclohexadiene 19 B1u 108 57 -51 1.887
C6H8 1,4-Cyclohexadiene 23 B2g 403 319 -84 1.265
CO+ carbon monoxide cation 1 Σ 2184 2739 555 0.797
C6H6 Benzvalene 10 A1 996 728 -268 1.368
C6H10 2-Hexyne 25 A' 115 88 -27 1.303
C6H10 2-Hexyne 38 A" 392 245 -147 1.601
H2CS- thioformaldehyde anion 4 B1 450 -132 -582 -3.401
CH2ClCCCl 1,3-dichloropropyne 14 A" 337 215 -122 1.566
CaO Calcium monoxide 1 Σ 723 505 -217 1.430
LiOH lithium hydroxide 3 Π 257 396 140 0.648
NaOH sodium hydroxide 3 torsion Π 300 197 -103 1.520
CH2NH+ Methanimine cation 4 A' 1370 1795 425 0.763
CN Cyano radical 1 Σ 2042 2715 673 0.752
C2H Ethynyl radical 2 Σ 1841 2344 503 0.785
C2H Ethynyl radical 3 torsion Π 372 764 393 0.486
CH3 Methyl radical 2 torsion A2" 606 409 -197 1.483
CH2OH Hydroxymethyl radical 8 torsion A 482 711 229 0.678
CH2OH Hydroxymethyl radical 9 torsion A 234 462 228 0.506
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 860 -276 1.321
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 115 -149 2.305
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 88 -270 4.083
C6H6 2,4-Hexadiyne 14 E' 353 108 -245 3.258
CHCl2 dichloromethyl radical 4 A' 190 306 116 0.620
CH2CHO Vinyloxy radical 10 A" 703 1017 314 0.691
C4H6 Methylenecyclopropane 17 B1 360 258 -102 1.395
CH2Cl chloromethyl radical 4 B1 402 -217 -619 -1.851
HNC+ hydrogen isocyanide cation 2 Σ 2195 2658 463 0.826
C2Cl2 dichloroacetylene 4 Πg 333 -72 -405 -4.601
C2Cl2+ dichloroacetylene cation 5 Πu 233 177 -56 1.316
BF3+ boron trifluoride cation 5 B2 1791 3289 1498 0.544
O2+ diatomic oxygen cation 1 Σg 1873 1408 -465 1.331
HN3+ Hydrazoic acid cation 2 A' 1850 3226 1376 0.573
FOOF Perfluoroperoxide 3 A 360 233 -127 1.548
FOOF Perfluoroperoxide 4 torsion A 202 127 -75 1.585
CaBr2 Calcium dibromide 3 Πu 72 34 -38 2.133
HOCl+ hypochlorous acid cation 3 A' 830 1238 408 0.670
ZnCl Zinc monochloride 1 Σ 388 301 -87 1.289
O3 Ozone 3 B2 1042 2169 1127 0.480
NO Nitric oxide 1 Σ 1876 3383 1507 0.555
NO2 Nitrogen dioxide 3 B2 1618 2326 708 0.696
BCl3+ Boron Trichloride cation 3 E' 1104 1514 410 0.729
N2O4 Dinitrogen tetroxide 9 B2u 265 195 -70 1.356
N2O3 Dinitrogen trioxide 9 torsion A" 63 163 100 0.386
NaO2 Sodium superoxide 3 B2 333 1175 842 0.283
VO Vanadium monoxide 1 Σ 1002 1823 821 0.549
Li2O dilithium oxide 3 Πu 112 61 -50 1.825
SiC2 Silicon dicarbide 3 B2 196 146 -50 1.345
C3 carbon trimer 3 Πu 63 163 100 0.388
C5H5- cylopentadienyl anion 8 E1" 625 470 -155 1.329
C5H5- cylopentadienyl anion 14 E2" 600 445 -155 1.349
LiO2 Lithium dioxide 3 B2 509 1130 621 0.450
ClNO2 Nitryl chloride 3 A1 364 278 -85 1.307
SiH2D2 silane-d2 6 B1 2183 1575 -608 1.386
SiH2D2 silane-d2 8 B2 1601 2179 578 0.735
H3O+ hydronium cation 2 A1 954 729 -225 1.308
PO Phosphorus monoxide 1 Σ 1220 3580 2360 0.341
AlO Aluminum monoxide 1 Σ 965 746 -220 1.295
FOO Dioxygen monofluoride radical 1 A' 1487 2031 544 0.732
SCN thiocyanato radical 1 Σ 1942 2414 472 0.805
ClOO chloroperoxy radical 2 A' 414 1058 644 0.391
ClOO chloroperoxy radical 3 A' 201 488 287 0.413
B4H10 Tetraborane(10) 11 A1 785 570 -215 1.377
B4H10 Tetraborane(10) 12 A1 559 224 -335 2.492
B4H10 Tetraborane(10) 19 A2 662 400 -262 1.656
B4H10 Tetraborane(10) 36 B2 236 355 119 0.665
B5H9 pentaborane9 13 B1 240 591 351 0.406
B5H9 pentaborane9 16 B2 1036 772 -264 1.342
B5H9 pentaborane9 18 B2 600 475 -125 1.264
B5H9 pentaborane9 22 E 1409 1050 -359 1.341
OPCl Phosphorus oxychloride 2 A' 308 459 151 0.670
OPCl Phosphorus oxychloride 3 A' 492 288 -204 1.707
NCO isocyanato radical 1 Σ 1921 2360 438 0.814
H2OH2O water dimer 7 A' 143 205 62 0.697
H2OH2O water dimer 8 A' 103 152 49 0.676
H2OH2O water dimer 11 A" 108 167 59 0.649
H2POH Phosphinous acid 9 A" 375 273 -102 1.373
AsN Arsenic mononitride 1 Σ 1058 818 -240 1.293
Mg2 Magnesium diatomic 1 Σg 48 27 -21 1.775
ClOF3 Chlorine trifluoride oxide 5 A' 319 248 -71 1.288
CHFCl Chlorofluoromethyl radical 6 A 540 399 -141 1.355
ZnCH3 Zinc monomethyl 6 E 315 622 307 0.506
H2CNCN cyanamide, methylene 3 A' 2208 2973 765 0.743
H2CNCN cyanamide, methylene 4 A' 1621 2070 449 0.783
SNO Nitrogen oxide sulfide 3 A' 792 534 -259 1.484
SSCl2 Thiothionyl chloride 5 A" 377 292 -85 1.289
ONONO Nitrosyl nitrite 9 B2 380 222 -158 1.714