Towards solvation simulations with a combined ab initio molecular dynamics and molecular mechanics approach

The combined quantum mechanics and molecular mechanics method has been implemented within the framework of the Projector Augmented Wave Car- Parrinello method for explicit solvent simulations. The approach has been evaluated for 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 bimolecular interactions between a water molecule and a set of organic molecules calculated 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 interaction energies that ranged from -0.3 to -29.3 kcal/mol. (C) 2000 Elsevier Science B.V.