Splitting of time scales

A recent development in multiscale integration has been the discovery that the scales of electrostatics forces are not well separated in current splittings used in MD, particularly with periodic boundary conditions [76]. This imposes outer time step limitations of 8fs. Recent work of Batcho and Schlick [6] has produced a splitting of the Ewald summation that separates scales well. This formulation should allow an enhanced application of the mixed implicit-explicit schemes proposed here. In addition to providing a good separation of time scales, the splitting should be such that the solution of the implicit equations on the forces have quick convergence.