Parallel FFT-based Poisson solver for isolated three-dimensional systems

We describe an implementation to solve Poisson's equation for an isolated system on a unigrid mesh using FFTs. The method solves the equation globally on mesh blocks distributed across multiple processes on a distributed-memory parallel computer. Test results to demonstrate the convergence and scaling properties of the implementation are presented. The solver is offered to interested users as the library PSPFFT. Program summary Program title: PSPFFT Catalogue identifier: AEJK_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEJK_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 110 243 No. of bytes in distributed program, including test data. etc.: 16332 181 Distribution format: tar.gz Programming language: Fortran 95 Computer: Any architecture with a Fortran 95 compiler, distributed memory clusters Operating system: Linux, Unix Has the code been vectorized or parallelized?: Yes, using MPI. An arbitrary number of processors may be used (subject to some constraints). The program has been tested on from 1 up to similar to 13 000 processors. RAM: Depends on the problem size, approximately 170 MBytes for 48(3) cells per process. Classification: 4.3, 6.5 External routines: MPI (http://www.mcs.anl.gov/mpi/), FFTW (http://www.fftw.org), Silo (https://wci.llnl..gov/codes/silon (only necessary for running test problem). Nature of problem: Solving Poisson's equation globally on unigrid mesh distributed across multiple processes on distributed memory system. Solution method: Numerical solution using multidimensional discrete Fourier Transform in a parallel Fortran 95 code. Unusual features: This code can be compiled as a library to be readily linked and used as a blackbox Poisson solver with other codes. Running time: Depends on the size of the problem, but typically less than 1 second per solve. (C) 2011 Elsevier By. All rights reserved.