Towards solvation simulations with a combined ab initio molecular dynamicsand molecular mechanics approach

The combined quantum mechanics and molecular mechanics method has been impl emented within the framework of the Projector Augmented Wave Car-Parrinello method for explicit solvent simulations. The approach has been evaluated f or its ability to represent the 'true' intermolecular interaction potential and its ability to perform energy conserving dynamics. The combined QM/MM potential has been parameterized to reproduce 27 hydrogen bonded bimolecula r interactions between a water molecule and a set of organic molecules calc ulated wholly at the density function theory level. For this training set, a root-mean-square deviation of 0.8 kcal/mol was achieved for the interacti on energies that ranged from -0.3 to -29.3 kcal/mol. (C) 2000 Elsevier Scie nce B.V. All rights reserved.