Crystal Geometry Optimization of ￥a-Lactam Antibiotics Using MMFF Parameters

摘要

A generic force field approach has been applied to geometry optimization of penam and cephem crystals. The crystalline state energy and force evaluation with the universal force field (MMFF: Merck Molecular Force Field) results in good agreements with the crystallographic data. Bond lengths are usually correct to within 0.02 ∈ and bond angles usually to within 2.5∑. The conformation of the モ-lactam bicyclic rings in the crystal environment is also well reproduced. The results thus demonstrate the applicability of MMFF to modeling of newer molecular constructs in condensed phase.