return to home page

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

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

Isomers of C6H12O2

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C6H12O2 598981 Methyl pivalate   sketch of Methyl pivalate
b C6H12O2 142621 Hexanoic acid 0.0 sketch of Hexanoic acid
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical AM1 84.0 a
0.0 b
PM3 62.1 a
0.0 b
0.0 b
composite G1 -1474.5 a
0.0 b
G2MP2 -1472.0 a
0.0 b
G2 -1471.8 a
0.0 b
G3 -1470.1 a
0.0 b
G3B3 14.2 a
0.0 b
0.0 b
CBS-Q 20.5 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 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.