Reference Energies in Semiempirical Parametrizations

The MNDO scheme has been reparametrized for hydrocarbons using both molecular binding energies and heats of formation at 0 K as experimental reference data. Compared with MNDO, there are only minor changes in the optimized parameters, and the results are essentially of the same accuracy. These tests justify the use of heats of formation at 298 K as reference data in the original MNDO parametrization.