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

Isomers of C3H3

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C3H3+ 2932787 Propargyl cation   sketch of Propargyl cation
b C3H3+ 9000220 cyclopropenyl cation 0.0 sketch of cyclopropenyl cation
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 1138.7 a
PM3 1145.0 a
PM6 151.1 a
0.0 b
composite G1 104.6 a
0.0 b
G2MP2 107.0 a
0.0 b
G2 107.3 a
0.0 b
G3 104.5 a
0.0 b
G3B3 105.8 a
0.0 b
G3MP2 103.1 a
0.0 b
G4 108.4 a
0.0 b
CBS-Q 98.2 a
0.0 b

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 Calculated; Vibrations; Scale Factors; Scale factors to list vibrational scaling factors.
See section Calculated; Vibrations; Scale Factors; Calculate a scale factor to calculate a vibrational scaling factor for a given set of molecules.