the results of mndo, am1 and pm3 semi-empirical calculations and hf/6-31g*, mp/6-31g*, mp2/6-311+g**, and b3lyp/6-311g** and qcisd/6-31g* ab initio methods for angle strain and conjugation effects in twist-boat, boat, and half-chair geometries of (z,z,z)-cycloocta-1,3,5-triene indicate that all methods, except pm3, predict wrong ordering of the conformations.

This is a review of molecular modelling techniques which may be applied to studies of energetic materials. It focusses on ab initio ('first-principles') molecular orbital calculations, since these methods offer the greatest accuracy. Since ab initio calculations are very computer-intensive, approximate MO methods are also discussed, which offer reasonably accurate predictions with reduced calcu...

Geometry optimizations for several spin states of the iron(III)-S-methyl- porphyrin complex, the iron (III)-oxo-S-methyl-porphyrin complex and the respective anions were performed in order to examine models for intermediates in the oxidative cycle of cytochrome P450. The aim of this study was to obtain insights into the ground states of the intermediates of this catalytic cycle and to use the a...