Comments on P3M, FMM, and the Ewald method for large periodic Coulombic systems Original Research Article

Prompted by the need to simulate large molecular or gravitational systems and the availability of multiprocessor computers, alternatives to the standard Ewald calculation of Coulombic interactions have been developed. The two most popular alternatives, the fast multipole method (FMM) and the particle-particle particle-mesh (P3M) method are compared here to the Ewald method for a single processor machine. Parallel processor implementations of the P3M and Ewald methods are compared. The P3M method is found to be both faster than the FMM and easier to implement efficiently as it relies on commonly available software (FFT subroutines). Both the Ewald and P3M method are easily implemented on parallel architectures with the P3M method the clear choice for large systems.