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

Relative enthalpies of isomers - Comparison of 298.15K enthalpies (kJ mol-1)

Isomers of C2H6N2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a CH3NNCH3 4143413 DimethylDiazineE   sketch of DimethylDiazineE
b CH3NNCH3 4143424 DimethylDiazineZ   sketch of DimethylDiazineZ
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1
338.2 b
PM3
331.7 b
PM6
318.6 b
composite G1
NC
G2MP2
NC
G2
NC
G3
NC
G3B3
NC
G4
NC
CBS-Q
NC

Methods with standard basis sets
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.