return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) 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 MP2=FULL/3-21G*
Calculated values were scaled by 0.948.

Species Name mode Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 482 -130 1.270
C2H4+ Ethylene cation 4 Au 84 -253 -337 -0.332
CH3OH Methyl alcohol 12 A" 200 364 164 0.550
HCN+ hydrogen cyanide cation 2 Σ 1800 2828 1028 0.637
HCN+ hydrogen cyanide cation 1 Σ 3050 3823 773 0.798
CH3COOCH3 methyl acetate 26 A" 136 97 -39 1.408
CH3COOCH3 methyl acetate 27 A" 110 86 -24 1.283
C3F8 perfluoropropane 13 A2 276 201 -75 1.373
C10H8 naphthalene 27 B2g 770 529 -241 1.455
C3H6O 2-Propen-1-ol 24 A 188 93 -95 2.019
CO2 Carbon dioxide 3 Πu 667 523 -144 1.275
C5H8 Cyclopentene 18 A' 254 129 -125 1.972
C4H6O2 2,3-Butanedione 16 Au 48 70 22 0.687
C4H6O2 2,3-Butanedione 21 Bg 240 94 -146 2.563
CH2N4 1H-Tetrazole 11 A' 925 700 -225 1.322
CH2NN diazomethane 6 B1 406 251 -155 1.616
C4H2 Diacetylene 7 Πg 482 -693 -1175 -0.695
C4H2 Diacetylene 8 Πu 630 497 -133 1.268
C4H2 Diacetylene 9 Πu 231 120 -111 1.918
C2H2N4 sym-tetrazine 3 Ag 1009 792 -217 1.273
C2H2N4 sym-tetrazine 13 B2u 883 664 -219 1.330
F2CCCF2 tetrafluoroallene 11 E 90 62 -28 1.442
C2H3NO3 Oxamic acid 3 A' 2600 3322 722 0.783
C2H3NO3 Oxamic acid 15 A' 328 255 -73 1.285
C2H3NO3 Oxamic acid 17 A" 815 634 -181 1.286
C2H3NO3 Oxamic acid 21 A" 162 109 -53 1.481
C3H6O Oxetane 7 A1 1018 800 -218 1.273
C3H6O Oxetane 18 B1 90 25 -65 3.657
C3H6O Oxetane 23 B2 1228 918 -310 1.338
Zn(CH3)2 dimethyl zinc 11 E' 134 -98 -232 -1.370
C5H8 1,4-Pentadiene 16 A 137 296 159 0.462
C5H8 1,4-Pentadiene 17 A 102 80 -22 1.282
C6H8 1,4-Cyclohexadiene 19 B1u 108 58 -50 1.866
FCN Cyanogen fluoride 3 Π 451 354 -97 1.274
C6H6 Benzvalene 10 A1 996 784 -212 1.271
CCl2 dichloromethylene 3 B2 758 596 -162 1.273
H2CS- thioformaldehyde anion 4 B1 450 141 -309 3.197
CN Cyano radical 1 Σ 2069 2480 412 0.834
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 221 77 0.652
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 333 -123 1.368
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 110 -61 1.553
FCO+ Carbonyl fluoride cation 3 Π 650 445 -205 1.460
CH2OH Hydroxymethyl radical 8 A 482 705 223 0.684
CH2OH Hydroxymethyl radical 9 A 234 429 195 0.546
C2H Ethynyl radical 3 Π 372 767 396 0.484
CH3 Methyl radical 2 A2" 606 405 -202 1.498
OH- hydroxide anion 1 Σ 3738 2669 -1070 1.401
CHCl2 dichloromethyl radical 4 A' 190 298 108 0.638
HCCN cyanomethylene 5 Π 129 -392 -521 -0.329
N2 Nitrogen diatomic 1 Σg 2359 1751 -607 1.347
O2 Oxygen diatomic 1 Σg 1580 914 -666 1.728
O2 Oxygen diatomic 1 Σg 1484 547 -936 2.712
HNCS Isothiocyanic acid 4 A' 615 468 -147 1.315
H2CCCCH2 Butatriene 10 B2g 544 209 -335 2.601
CH3SO2NH2 methanesulfonamide 11 A' 689 506 -183 1.362
H2CCCCH2 Butatriene 16 B3g 330 226 -104 1.462
C6H6 Trimethylenecycopropane 20 E" 340 257 -83 1.324
HClO4 perchloric acid 12 A" 191 114 -77 1.675
N2O Nitrous oxide 1 Σ 2282 1794 -488 1.272
N2O Nitrous oxide 2 Σ 1298 974 -325 1.333
N2O Nitrous oxide 3 Π 596 458 -138 1.302
SOCl2 thionyl chloride 6 A" 284 223 -61 1.271
H2O2 Hydrogen peroxide 4 A 371 145 -226 2.563
HN3 hydrogen azide 4 A' 1151 878 -272 1.310
NO+ nitric oxide cation 1 Σ 2377 1432 -944 1.659
CH2CHO Vinyloxy radical 10 A" 703 1020 317 0.689
FOOF Perfluoroperoxide 1 A 1210 872 -338 1.388
FOOF Perfluoroperoxide 4 A 202 134 -68 1.510
FOOF Perfluoroperoxide 5 B 614 883 269 0.696
NS+ nitrogen sulfide cation 1 Σ 1415 1084 -331 1.306
VO Vanadium monoxide 1 Σ 1011 2165 1154 0.467
FO Oxygen monofluoride 1 Σ 1053 1747 694 0.603
O3 Ozone 3 B2 1042 2954 1912 0.353
O2+ diatomic oxygen cation 1 Σg 1906 667 -1239 2.858
NO Nitric oxide 1 Σ 1904 4212 2308 0.452
NO2 Nitrogen dioxide 3 B2 1618 3062 1444 0.528
N2O3 Dinitrogen trioxide 2 A' 1652 1226 -426 1.348
N2O3 Dinitrogen trioxide 3 A' 1305 1027 -278 1.270
N2O3 Dinitrogen trioxide 7 A' 205 106 -99 1.941
N2O3 Dinitrogen trioxide 9 A" 63 187 124 0.336
Li2O dilithium oxide 3 Πu 112 75 -36 1.486
C3 carbon trimer 3 Πu 63 -129 -192 -0.493
SO Sulfur monoxide 1 Σ 1069 822 -246 1.300
BeF2 Beryllium fluoride 3 Πu 343 257 -86 1.336
TiO Titanium monoxide 1 Σ 1009 1859 850 0.543
PO2 Phosphorus dioxide 3 B2 1328 2425 1098 0.547
PS phosphorus sulfide 1 Σ 739 1194 455 0.619
BrNO Nitrosyl bromide 1 A' 1832 1268 -564 1.445
CaS Calcium sulfide 1 Σ 462 363 -99 1.272
NH2- amino anion 3 B2 3190 2637 -553 1.210
OPCl Phosphorus oxychloride 2 A' 308 460 152 0.669
OPCl Phosphorus oxychloride 3 A' 492 287 -205 1.715
Na2 Sodium diatomic 1 Σg 159 124 -35 1.286
H2POH Phosphinous acid 9 A" 375 216 -159 1.734
H3O+ hydronium cation 2 A1 954 342 -613 2.794
AsN Arsenic mononitride 1 Σ 1069 704 -364 1.518
Mg2 Magnesium diatomic 1 Σg 51 40 -11 1.285
ClONO2 Chlorine nitrate 2 A' 1293 1014 -279 1.275
CaOH Calcium monohydroxide 3 Π 353 524 171 0.674
SCN thiocyanato radical 1 Σ 1942 2595 653 0.748
INO Nitrosyl iodide 1 A' 1785 1300 -485 1.373
INO Nitrosyl iodide 2 A' 216 436 220 0.495
INO Nitrosyl iodide 3 A' 470 194 -276 2.418
H2OH2O water dimer 6 A' 311 503 192 0.618
H2OH2O water dimer 7 A' 143 266 123 0.538
H2OH2O water dimer 8 A' 103 206 103 0.500
H2OH2O water dimer 10 A" 523 806 283 0.649
H2OH2O water dimer 11 A" 108 213 105 0.507
H2OH2O water dimer 12 A" 88 131 43 0.673
HOClO Chlorous acid 4 A 592 463 -128 1.277
BrONO2 Bromine nitrate 2 A' 1288 998 -290 1.291
BrONO2 Bromine nitrate 8 A" 728 575 -153 1.267
ZnCH3 Zinc monomethyl 6 E 315 596 281 0.528
N2H2 (E)-diazine 3 Ag 1529 1085 -444 1.409
H2COO dioxymethyl 6 A' 908 583 -325 1.559
NNS Nitrogen sulfide 1 Σ 2048 1402 -646 1.460
ClONO chlorine nitrite 1 A' 1715 1209 -506 1.419
S2N2 Disulfur dinitride 1 Ag 913 619 -294 1.475
S2N2 Disulfur dinitride 2 Ag 632 485 -147 1.303
BrONO Bromine nitrite 1 A' 1723 1211 -512 1.423
ONONO Nitrosyl nitrite 1 A1 1740 1153 -587 1.509
ONONO Nitrosyl nitrite 6 B1 140 109 -31 1.283
ONONO Nitrosyl nitrite 7 B2 1697 1110 -587 1.529