Long Time Step MD Simulations Using Split Integration Symplectic Method

The design and analysis of an explicit Split Integration Symplectic Method (SISM) for molecular dynamics (MD) simulations is described. SISM uses an analytical treatment of high frequency motions within a second order generalized leapfrog scheme. SISM is up to an order of magnitude faster than the commonly used leapfrog-Verlet (LFV) algorithm which is of the same order and complexity as SISM. The main restriction on time step in the general MD simulations, which stems from the high-frequency motion is, to a large extent, overcome in this approach. The simulation results for selected examples show that SISM posses long term stability and the ability to use long time steps. This should significantly extend the scope of the presently used algorithms and thus contribute to the general applicability of MD algorithms.