Acceleration of canonical molecular dynamics simulations using macroscopic expansion of the fast multipole method combined with the multiple timestep integrator algorithm

A canonical molecular dynamics (MD) simulation was accelerated by using an efficient implementation of the multiple timestep integrator algorithm combined with the periodic fast multiple method (MEFMM) for both Coulombic and van der Waals interactions. Although a significant reduction in computational cost has been obtained previously by using the integrated method, in which the MEFMM was used only to calculate Coulombic interactions (Kawata, M., and Mikami, M., 2000, J. Comput. Chen., in press), the extension of this method to include van der Waals interactions yielded further acceleration of the overall MD calculation by a factor of about two. Compared with conventional methods, such as the velocity-Verlet algorithm combined with the Ewald method (timestep of 0.25 fs), the speedup by using the extended integrated method amounted to a factor of 500 for a 100 ps simulation. Therefore, the extended method reduces substantially the computational effort of large scale MD simulations.