National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
NIST Standard Reference Database 101
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
XOlder CCCBDB versions
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers

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XIII.F.2. (III.B.7.b.) (IV.C.7.) (XVIII.B.2.)

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 CCSD(T)/6-31+G**
Calculated values were scaled by 0.9596.

Species Name mode Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 383 -229 1.598
CH3 Methyl radical 2 A2" 606 466 -140 1.301
CH3CO Acetyl radical 4 A' 1420 3061 1641 0.464
CaOH Calcium monohydroxide 2 Σ 353 611 258 0.578
CaOH Calcium monohydroxide 3 Π 609 384 -225 1.584
H2OH2O water dimer 8 A' 103 161 58 0.638
H2OH2O water dimer 11 A" 108 159 51 0.680
H2OH2O water dimer 12 A" 88 135 47 0.653