title: Reconsidering Dispersion Potentials: Reduced Cutoffs in Mesh-Based Ewald Solvers Can Be Faster Than Truncation.
abstract: Long-range dispersion interactions have a critical influence on physical quantities in simulations of inhomogeneous systems. However, the perceived computational overhead of long-range solvers has until recently discouraged their implementation in molecular dynamics packages. Here, we demonstrate that reducing the cutoff radius for local interactions in the recently introduced particle-particle particle-mesh (PPPM) method for dispersion [Isele-Holder et al., J. Chem. Phys., 2012, 137, 174107] can actually often be faster than truncating dispersion interactions. In addition, because all long-range dispersion interactions are incorporated, physical inaccuracies that arise from truncating the potential can be avoided. Simulations using PPPM or other mesh Ewald solvers for dispersion can provide results more accurately and more efficiently than simulations that truncate dispersion interactions. The use of mesh-based approaches for dispersion is now a viable alternative for all simulations containing dispersion interactions and not merely those where inhomogeneities were motivating factors for their use. We provide a set of parameters for the dispersion PPPM method using either ik or analytic differentiation that we recommend for future use and demonstrate increased simulation efficiency by using the long-range dispersion solver in a series of performance tests on massively parallel computers.
authors.affiliation: Aachener Verfahrenstechnik: Molecular Simulations and Transformations and AICES Graduate School, RWTH Aachen University , Schinkelstraße 2, 52062 Aachen, Germany.
authors.forename: Rolf E
authors.initials: RE
authors.lastname: Isele-Holder
authors.affiliation: Aachener Verfahrenstechnik: Molecular Simulations and Transformations and AICES Graduate School, RWTH Aachen University , Schinkelstraße 2, 52062 Aachen, Germany.|Loyola University , 6363 Saint Charles Avenue, New Orleans, Louisiana 70118, United States of America.
authors.forename: Wayne
authors.initials: W
authors.lastname: Mitchell
authors.affiliation: Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, United States of America.
authors.forename: Jeff R
authors.initials: JR
authors.lastname: Hammond
authors.affiliation: International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy.
authors.forename: Axel
authors.initials: A
authors.lastname: Kohlmeyer
authors.affiliation: Aachener Verfahrenstechnik: Molecular Simulations and Transformations and AICES Graduate School, RWTH Aachen University , Schinkelstraße 2, 52062 Aachen, Germany.
authors.forename: Ahmed E
authors.initials: AE
authors.lastname: Ismail