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 HF/6-31+G**
Calculated values were scaled by 0.9042.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 171 58 0.661
CH3CONH2 Acetamide 20 A 259 189 -70 1.372
CH3COCH3 Acetone 12 A2 77 29 -48 2.687
CH3OH Methyl alcohol 12 A" 200 293 93 0.683
C2H4+ Ethylene cation 4 Au 84 343 259 0.245
C2H5Br Ethyl bromide 4 A' 1451 2941 1490 0.493
C2H5Br Ethyl bromide 5 A' 1451 2879 1428 0.504
C2H5Br Ethyl bromide 6 A' 1386 2879 1493 0.481
C2H5Br Ethyl bromide 8 A' 1061 1464 403 0.724
C2H5Br Ethyl bromide 9 A' 964 1462 498 0.659
C2H5Br Ethyl bromide 10 A' 583 1462 879 0.399
C2H5Br Ethyl bromide 11 A' 290 1400 1110 0.207
CBr2F2 Methane, dibromodifluoro- 3 A1 140 337 197 0.416
CH3COOCH3 methyl acetate 27 A" 110 77 -33 1.425
CF2CCl2 difluorodichloroethylene 7 B1 1327 647 -680 2.050
CF2CCl2 difluorodichloroethylene 8 B1 989 334 -655 2.961
CF2CCl2 difluorodichloroethylene 12 B2 323 184 -139 1.751
C3H6O 2-Propen-1-ol 24 A 188 109 -79 1.722
C4H8O Furan, tetrahydro- 33 B 137 70 -67 1.963
C5H8 Cyclopentene 18 A' 254 141 -113 1.799
C2H2N4 sym-tetrazine 18 B3u 254 367 113 0.693
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 603 252 0.582
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 352 -857 3.439
C4H6O2 2,3-Butanedione 21 Bg 240 117 -123 2.047
C6H4 Benzyne 24 B2 472 281 -191 1.678
C2H3NO3 Oxamic acid 3 A' 2600 3471 871 0.749
C2H3NO3 Oxamic acid 21 A" 162 48 -114 3.369
C3O2 Carbon suboxide 7 Πu 61 128 67 0.478
HCNO fulminic acid 5 Π 224 548 324 0.409
C5H8 1,4-Pentadiene 16 A 137 289 152 0.473
C5H8 1,4-Pentadiene 33 B 331 99 -232 3.355
C2F2 difluoroacetylene 4 Πg 270 442 172 0.611
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.675
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 114 -57 1.494
C2H+ Ethynyl cation 3 Π 550 840 290 0.654
CH3 Methyl radical 2 A2" 606 378 -229 1.606
CH2OH Hydroxymethyl radical 8 A 482 719 237 0.671
CH2OH Hydroxymethyl radical 9 A 234 365 131 0.641
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 76 -188 3.482
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 82 -276 4.349
CHCl2 dichloromethyl radical 4 A' 190 293 103 0.648
FOOF Perfluoroperoxide 2 A 630 1020 390 0.618
FOOF Perfluoroperoxide 5 B 614 1010 396 0.608
PCl5 Phosphorus pentachloride 2 A1' 370 268 -102 1.378
N2O4 Dinitrogen tetroxide 3 Ag 265 410 145 0.647
N2O4 Dinitrogen tetroxide 4 Au 82 45 -37 1.827
N2O3 Dinitrogen trioxide 6 A' 241 390 149 0.617
N2O3 Dinitrogen trioxide 7 A' 205 327 122 0.626
N2O3 Dinitrogen trioxide 8 A" 414 618 204 0.670
N2O3 Dinitrogen trioxide 9 A" 63 96 33 0.655
NS Mononitrogen monosulfide 1 Σ 1219 810 -409 1.505
SiN Silicon nitride 1 Σ 1151 837 -315 1.376
VO Vanadium monoxide 1 Σ 1011 524 -487 1.929
C3 carbon trimer 3 Πu 63 149 86 0.426
SiP Silicon monophosphide 1 Σ 616 421 -194 1.461
CaOH Calcium monohydroxide 2 Σ 353 543 190 0.650
CaOH Calcium monohydroxide 3 Π 609 417 -192 1.459
Cu2 Copper dimer 1 Σg 265 167 -97 1.580
PS phosphorus sulfide 1 Σ 739 491 -248 1.505
CP Carbon monophosphide 1 Σ 1240 911 -329 1.362
S3- Sulfur trimer anion 3 B2 594 447 -147 1.328
BH3CO Borane carbonyl 4 A1 691 486 -205 1.422
SF5Cl sulfur chloropentafluoride 7 B2 505 332 -173 1.520
SF5Cl sulfur chloropentafluoride 11 E 397 260 -137 1.525
H3O+ hydronium cation 2 A1 954 709 -246 1.347
AlO Aluminum monoxide 1 Σ 979 699 -280 1.400
C2H4O4 Formic acid dimer 13 Au 1050 69 -981 15.279
C2H4O4 Formic acid dimer 17 Bu 3084 3496 412 0.882
C2H4O4 Formic acid dimer 24 Bu 268 197 -71 1.362
ClOO chloroperoxy radical 1 A' 1443 1081 -362 1.335
ClOO chloroperoxy radical 2 A' 414 648 234 0.639
ClOO chloroperoxy radical 3 A' 201 410 209 0.491
PN+ phosphorus nitride cation 1 Σ 1200 684 -516 1.753
Cl3- trichloride anion 2 Σu 327 -100 -427 -3.257
F3- trifluoride anion 2 Σu 550 -500 -1050 -1.100
H2POH Phosphinous acid 9 A" 375 263 -113 1.429
Mg2 Magnesium diatomic 1 Σg 51 336 285 0.152
ZnCH3 Zinc monomethyl 6 E 315 581 266 0.542
NNS Nitrogen sulfide 2 Σ 752 526 -226 1.430
ClONO chlorine nitrite 4 A' 406 683 277 0.594
CH3BO Borane, methyloxo- 7 E 897 1425 528 0.629
HSO3 HOSO2 4 A 1097 823 -274 1.333
ONONO Nitrosyl nitrite 9 B2 380 697 317 0.545