A particle-particle particle-multigrid method for long-range interactions in molecular simulations

A fast method of order O(N) is proposed to calculate interaction energies and forces in molecular systems with open boundaries, exerted by long range Coulomb interactions. The method consists of a fast multigrid Poisson solver for the far field smooth part of the potential and a particle-particle based method for the near field contribution. Boundary conditions are calculated with a multipole expansion method. Test cases are performed for the performance of the method.