return to home page

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

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

Isomers of C5H7

index Species CAS number Name Relative experimental enthalpy (kJ mol-1) sketch
a C5H7 10577658 cyclopentenyl radical   sketch of cyclopentenyl radical
b C5H7 14362084 1,3-pentadienyl radical   sketch of 1,3-pentadienyl radical
The calculated enthalpies include the calculated and scaled vibrational zero-point energy.
Methods with predefined basis sets
semi-empirical PM6 366.6 a
406.7 b
composite G1 NC
G2MP2 NC
G2 NC
G3 NC
G3B3 NC
NC
G4 NC
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.