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
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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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IV.A.4. (XIV.F.)

Relative enthalpies of isomers - Comparison of 0K enthalpies (kJ mol-1)

Isomers of C12H8

2015 06 30 15:39
index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C12H8 208968 Acenaphthylene   sketch of Acenaphthylene
b C12H8 259790 biphenylene   sketch of biphenylene
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets

Methods with standard basis sets
3-21G* 6-31G* 6-311G* 6-311G** 6-31G(2df,p) cc-pVTZ aug-cc-pVTZ
hartree fock HF   0.0 a
152.3 b
density functional BLYP   0.0 a
138.9 b
B3LYP         0.0 a
144.0 b
wB97X-D 0.0 a
160.3 b
0.0 a
143.9 b
  0.0 a
144.0 b
  0.0 a
143.6 b
0.0 a
144.2 b
3-21G* 6-31G* 6-311G* 6-311G** 6-31G(2df,p) cc-pVTZ aug-cc-pVTZ
Moller Plesset perturbation MP2   0.0 a
157.3 b
0.0 a
157.0 b
3-21G* 6-31G* 6-311G* 6-311G** 6-31G(2df,p) cc-pVTZ aug-cc-pVTZ
NC = not calculated
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.
gaw refers to the group additivity method implemeted in the NIST Chemistry Webbook.

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.