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 mPW1PW91/3-21G*
Calculated values were scaled by 0.9496.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 397 139 0.651
CH3OH Methyl alcohol 12 A" 200 367 167 0.545
CH3COCH3 Acetone 12 A2 77 61 -16 1.267
C2H4+ Ethylene cation 4 Au 84 -485 -569 -0.174
CHONH2 formamide 12 A" 289 497 208 0.581
HNCO Isocyanic acid 4 A' 777 574 -202 1.352
HNCO Isocyanic acid 5 A' 577 427 -150 1.352
CBr2F2 Methane, dibromodifluoro- 3 A1 140 326 186 0.430
C3F8 perfluoropropane 13 A2 276 200 -76 1.382
CF2CCl2 difluorodichloroethylene 7 B1 1327 631 -696 2.102
CF2CCl2 difluorodichloroethylene 8 B1 989 329 -660 3.005
CF2CCl2 difluorodichloroethylene 12 B2 323 177 -146 1.828
C3H6O 2-Propen-1-ol 22 A 377 297 -81 1.272
C3H6O 2-Propen-1-ol 24 A 188 98 -90 1.921
C2H2O2 Ethanedial 7 Au 127 194 67 0.656
CH3OCHO methyl formate 18 A" 130 76 -54 1.711
C4H8O2 1,4-Dioxane 19 Au 288 220 -68 1.311
C5H8 Cyclopentene 18 A' 254 126 -128 2.014
N2H4 Hydrazine 6 A 780 603 -177 1.293
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 582 231 0.603
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 354 -855 3.415
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 384 -149 1.390
C6F6 hexafluorobenzene 8 B2g 243 185 -58 1.312
C6F6 hexafluorobenzene 20 E2u 175 135 -40 1.300
C4H6O2 2,3-Butanedione 16 Au 48 36 -12 1.332
C4H6O2 2,3-Butanedione 21 Bg 240 61 -179 3.955
C2N2 Cyanogen 4 Πg 503 755 252 0.666
C5H12 Propane, 2,2-dimethyl- 12 T1 203 317 114 0.640
C2H3NO3 Oxamic acid 3 A' 2600 3381 781 0.769
C2H3NO3 Oxamic acid 15 A' 328 253 -75 1.297
C2H3NO3 Oxamic acid 21 A" 162 113 -49 1.427
C3H6O Oxetane 23 B2 1228 952 -276 1.289
C3O2 Carbon suboxide 7 Πu 61 145 84 0.420
HCNO fulminic acid 5 Π 224 528 304 0.425
Zn(CH3)2 dimethyl zinc 11 E' 134 -100 -234 -1.340
C5H8 1,4-Pentadiene 16 A 137 298 161 0.459
C5H8 1,4-Pentadiene 17 A 102 77 -25 1.316
C4N2 2-Butynedinitrile 6 Πg 504 904 400 0.557
C4N2 2-Butynedinitrile 8 Πu 472 681 209 0.693
LiOH lithium hydroxide 3 Π 257 403 146 0.637
SiF2+ Silicon difluoride cation 2 A1 350 274 -76 1.278
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 218 74 0.659
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.336
FCO+ Carbonyl fluoride cation 3 Π 650 499 -151 1.304
C2H Ethynyl radical 3 Π 372 544 172 0.684
CH3 Methyl radical 2 A2" 606 475 -132 1.278
CH2OH Hydroxymethyl radical 9 A 234 399 165 0.587
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.317
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 142 -122 1.864
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 95 -263 3.766
OH- hydroxide anion 1 Σ 3738 2663 -1075 1.404
C2Cl2 dichloroacetylene 4 Πg 333 499 166 0.667
HClO4 perchloric acid 12 A" 191 130 -61 1.465
HF Hydrogen fluoride 1 Σ 4138 3544 -594 1.168
NH3 Ammonia 2 A1 950 691 -259 1.375
H2O2 Hydrogen peroxide 4 A 371 63 -308 5.864
O2+ diatomic oxygen cation 1 Σg 1906 1440 -466 1.324
FOOF Perfluoroperoxide 1 A 1210 952 -258 1.271
FOOF Perfluoroperoxide 5 B 614 932 318 0.659
BeF2 Beryllium fluoride 3 Πu 343 255 -88 1.343
BrF5 bromine pentafluoride 6 B2 281 211 -70 1.333
CaF2 Calcium difluoride 2 A1 120 17 -103 7.151
PCl5 Phosphorus pentachloride 2 A1' 370 260 -110 1.424
N2O4 Dinitrogen tetroxide 9 B2u 265 196 -69 1.349
N2O3 Dinitrogen trioxide 9 A" 63 153 90 0.413
Li2O dilithium oxide 3 Πu 112 75 -37 1.496
C3 carbon trimer 3 Πu 63 159 96 0.398
CaOH Calcium monohydroxide 2 Σ 353 631 278 0.559
CaOH Calcium monohydroxide 3 Π 609 475 -134 1.282
TiO2 Titanium dioxide 1 A1 959 348 -611 2.753
ND3 Ammonia-d3 2 A1 748 524 -224 1.427
NH2- amino anion 1 A1 3122 2582 -540 1.209
NH2- amino anion 3 B2 3190 2621 -569 1.217
SF5Cl sulfur chloropentafluoride 5 B1 625 453 -172 1.380
SF5Cl sulfur chloropentafluoride 7 B2 505 307 -198 1.644
SF5Cl sulfur chloropentafluoride 11 E 397 240 -157 1.651
H3O+ hydronium cation 2 A1 954 474 -480 2.012
C2H4O4 Formic acid dimer 2 Ag 2949 2006 -943 1.470
C2H4O4 Formic acid dimer 13 Au 1050 94 -956 11.127
C2H4O4 Formic acid dimer 18 Bu 2939 2277 -662 1.291
C2H4O4 Formic acid dimer 24 Bu 268 434 166 0.617
ClOO chloroperoxy radical 1 A' 1443 1049 -394 1.376
ClOO chloroperoxy radical 3 A' 201 290 88 0.695
H2OH2O water dimer 6 A' 311 539 228 0.577
H2OH2O water dimer 7 A' 143 287 144 0.498
H2OH2O water dimer 8 A' 103 207 104 0.498
H2OH2O water dimer 10 A" 523 871 348 0.600
H2OH2O water dimer 11 A" 108 224 116 0.482
Na2 Sodium diatomic 1 Σg 159 81 -78 1.955
H2POH Phosphinous acid 9 A" 375 225 -151 1.671
Mg2 Magnesium diatomic 1 Σg 51 112 61 0.455
ZnCH3 Zinc monomethyl 6 E 315 630 315 0.500
CH3BO Borane, methyloxo- 7 E 897 1447 550 0.620
ONONO Nitrosyl nitrite 9 B2 380 601 221 0.632