OPTIMIZING EFFICIENCY OF PERTURBATIVE MONTE-CARLO METHOD

We introduce error weighting functions into the perturbative Monte Car lo method for use with a hybrid ab initio quantum mechanics/molecular mechanics (QM/MM) potential. The perturbative Monte Carlo approach int roduced earlier provides a means to reduce the number of full SCF calc ulations in simulations using a QM/MM potential by evoking perturbatio n theory to calculate energy changes due to displacements of an MM mol ecule. The use of weighting functions, introduced here, allows an opti mal number of MM molecule displacements to occur between the performan ce of the full self-consistent field calculations. This will allow the ab initio QM/MM approach to be applied to systems that require more a ccurate treatment of the QM and/or MM regions. (C) 1998 John Wiley & S ons, Inc.