National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
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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Calculated singlet - triplet Gaps for C2 (Carbon diatomic)

Vibrational zero-point energy (zpe) has not been included. Click on an entry for details including zpe.
singlet - triplet gaps in kJ mol-1.
Negative values indicate that the triplet state has a lower energy than the singlet state.
Methods with predefined basis sets

Methods with standard basis sets
3-21G* 6-31G* 6-311G** cc-pVTZ aug-cc-pVTZ
density functional wB97X-D -92 -107 -109 -109 -110
3-21G* 6-31G* 6-311G** cc-pVTZ aug-cc-pVTZ
For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.