return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 QCISD/6-311G*
Calculated values were scaled by 0.9574.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 392 133 0.660
CH3OH Methyl alcohol 12 A" 200 346 146 0.578
C2H4+ Ethylene cation 4 Au 84 -252 -336 -0.334
C2H2 Acetylene 4 Πg 612 408 -204 1.502
CH3CCH propyne 10 E 328 255 -73 1.285
CHONH2 formamide 12 A" 289 -257 -546 -1.123
CBr2F2 Methane, dibromodifluoro- 3 A1 140 332 192 0.422
CH3COOCH3 methyl acetate 27 A" 110 55 -55 1.987
CF2CCl2 difluorodichloroethylene 7 B1 1327 582 -745 2.281
CF2CCl2 difluorodichloroethylene 8 B1 989 320 -669 3.093
CF2CCl2 difluorodichloroethylene 11 B2 564 447 -117 1.261
CF2CCl2 difluorodichloroethylene 12 B2 323 183 -140 1.763
C9H8 Indene 40 A" 690 537 -153 1.285
C6H4O2 parabenzoquinone 17 B2g 241 173 -68 1.390
C6H4O2 parabenzoquinone 30 B3u 109 82 -27 1.325
C3H6O 2-Propen-1-ol 24 A 188 108 -80 1.744
C6H5Cl chlorobenzene 18 B1 685 490 -194 1.396
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 A2 193 147 -46 1.313
C5H8 Cyclopentene 18 A' 254 164 -90 1.551
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 526 175 0.667
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 336 -873 3.595
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 408 -125 1.306
NH2CN cyanamide 5 A' 408 682 274 0.598
C4H6O2 2,3-Butanedione 21 Bg 240 121 -119 1.981
C4H2 Diacetylene 7 Πg 482 -302 -784 -1.598
C4H2 Diacetylene 8 Πu 630 491 -139 1.283
CH3CCCH3 2-Butyne 16 E" 371 229 -142 1.617
C3H6O Oxetane 18 B1 90 37 -53 2.438
HCNO fulminic acid 5 Π 224 102 -122 2.194
C5H8 1,4-Pentadiene 16 A 137 291 154 0.472
HCCCl Chloroacetylene 5 Π 326 213 -113 1.534
C6H8 1,4-Cyclohexadiene 19 B1u 108 85 -23 1.266
LiOH lithium hydroxide 3 Π 257 389 132 0.660
NaOH sodium hydroxide 3 Π 300 202 -98 1.486
ZnO zinc monoxide 1 Σ 720 557 -163 1.292
ZnS Zinc sulfide 1 Σ 459 345 -114 1.331
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 215 71 0.669
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 331 -125 1.378
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 105 -66 1.636
CH3 Methyl radical 2 A2" 606 427 -179 1.419
CH2OH Hydroxymethyl radical 8 A 482 690 208 0.698
CH2OH Hydroxymethyl radical 9 A 234 451 217 0.519
CHCl2 dichloromethyl radical 4 A' 190 302 112 0.629
C4H6 Methylenecyclopropane 17 B1 360 267 -93 1.348
C2Cl2 dichloroacetylene 4 Πg 333 153 -180 2.177
N2 Nitrogen diatomic 1 Σg 2359 1579 -779 1.493
CaF2 Calcium difluoride 2 A1 120 55 -65 2.175
ZnCl Zinc monochloride 1 Σ 391 299 -92 1.307
N2O3 Dinitrogen trioxide 9 A" 63 137 74 0.458
Li2O dilithium oxide 3 Πu 112 55 -56 2.018
C3 carbon trimer 3 Πu 63 39 -25 1.643
TiO Titanium monoxide 1 Σ 1009 3162 2153 0.319
CaOH Calcium monohydroxide 2 Σ 353 627 274 0.563
CaOH Calcium monohydroxide 3 Π 609 366 -243 1.666
C4 Carbon tetramer 4 Πg 323 249 -74 1.298
SiH- silicon monohydride anion 1 Σ 2175 1675 -500 1.298
SF5Cl sulfur chloropentafluoride 5 B1 625 466 -159 1.342
SF5Cl sulfur chloropentafluoride 7 B2 505 317 -188 1.594
SF5Cl sulfur chloropentafluoride 11 E 397 248 -149 1.602
ZnH Zinc monohydride 1 Σ 1608 1105 -502 1.454
Cl3- trichloride anion 2 Σu 327 186 -141 1.755
H2OH2O water dimer 11 A" 108 164 56 0.660
H2POH Phosphinous acid 9 A" 375 263 -113 1.429
Mg2 Magnesium diatomic 1 Σg 51 14 -37 3.539
ZnCH3 Zinc monomethyl 6 E 315 614 299 0.513
CH3BO Borane, methyloxo- 7 E 897 1435 539 0.625