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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 QCISD(TQ)/6-31G*
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 328 -284 1.864
HCN+ hydrogen cyanide cation 3 Π 760 2335 1575 0.325
CH3CH2CH2CH3 Butane 5 Ag 1442 432 -1010 3.335
CH3CH2CH2CH3 Butane 8 Ag 1151 864 -287 1.333
CH3CH2CH2CH3 Butane 36 Bu 271 3122 2851 0.087
C3H6O Oxetane 18 B1 90 -71 -161 -1.267
HCNO fulminic acid 5 torsion Π 224 -240 -464 -0.935
FCO+ Carbonyl fluoride cation 3 Π 650 541 -109 1.203
C2H Ethynyl radical 3 torsion Π 372 219 -153 1.697
CH3 Methyl radical 2 torsion A2" 606 433 -174 1.401
CH2OH Hydroxymethyl radical 8 torsion A 482 741 259 0.650
CH2OH Hydroxymethyl radical 9 torsion A 234 449 215 0.521
OClO- Chlorine dioxide anion 2 A1 418 327 -91 1.280
AsSe Arsenic monoselenide 1 Σ 280 409 129 0.684
VO Vanadium monoxide 1 Σ 1002 2726 1724 0.367
Li2O dilithium oxide 3 Πu 112 81 -30 1.370
FO Oxygen monofluoride 1 Σ 1033 695 -338 1.485
C3 carbon trimer 3 Πu 63 12 -51 5.204
S3 Sulfur trimer 2 A1 281 562 281 0.500
SiH3 Silyl radical 4 E 922 2264 1342 0.407
SiH2D2 silane-d2 6 B1 2183 1642 -541 1.329
SiH2D2 silane-d2 8 B2 1601 2271 670 0.705
CaS Calcium sulfide 1 Σ 459 364 -95 1.260
H2OH2O water dimer 7 A' 143 205 62 0.696
H2OH2O water dimer 11 A" 108 160 52 0.675
ONNO NO dimer 4 torsion A2 117 188 71 0.623