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Title: Multilevel summation with B-spline interpolation for pairwise interactions in molecular dynamics simulations

Journal Article · · Journal of Chemical Physics
DOI:https://doi.org/10.1063/1.4943868· OSTI ID:22660801
 [1]; ;  [2];  [3]
  1. Beckman Institute, University of Illinois, 405 North Mathews Avenue, Urbana, Illinois 61801 (United States)
  2. Department of Computer Science, Purdue University, 305 North University Street, West Lafayette, Indiana 47907 (United States)
  3. Department of Mathematics, Purdue University, 150 North University Street, West Lafayette, Indiana 47907 (United States)

The multilevel summation method for calculating electrostatic interactions in molecular dynamics simulations constructs an approximation to a pairwise interaction kernel and its gradient, which can be evaluated at a cost that scales linearly with the number of atoms. The method smoothly splits the kernel into a sum of partial kernels of increasing range and decreasing variability with the longer-range parts interpolated from grids of increasing coarseness. Multilevel summation is especially appropriate in the context of dynamics and minimization, because it can produce continuous gradients. This article explores the use of B-splines to increase the accuracy of the multilevel summation method (for nonperiodic boundaries) without incurring additional computation other than a preprocessing step (whose cost also scales linearly). To obtain accurate results efficiently involves technical difficulties, which are overcome by a novel preprocessing algorithm. Numerical experiments demonstrate that the resulting method offers substantial improvements in accuracy and that its performance is competitive with an implementation of the fast multipole method in general and markedly better for Hamiltonian formulations of molecular dynamics. The improvement is great enough to establish multilevel summation as a serious contender for calculating pairwise interactions in molecular dynamics simulations. In particular, the method appears to be uniquely capable for molecular dynamics in two situations, nonperiodic boundary conditions and massively parallel computation, where the fast Fourier transform employed in the particle–mesh Ewald method falls short.

OSTI ID:
22660801
Journal Information:
Journal of Chemical Physics, Vol. 144, Issue 11; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
Country of Publication:
United States
Language:
English