NFFT-based extension of a particle simulation method using multigrid

In the calculation of electrostatic problems using multigrid methods, computationally the most expensive part is often the charge assignment to a grid. We show how to improve an existing multigrid method by using an NFFT-based scheme for this task. Numerical tests show that the new method outperforms the direct charge assignment schemes for the case where smooth charge distributions with large support are considered. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)