@article {10.3844/jmssp.2012.361.372, article_type = {journal}, title = {Multilevel Evaluation of Coulomb Lattice Sums of Charge Systems}, author = {Suwan, I. and Brandt, A. and Ilyin, V.}, volume = {8}, year = {2012}, month = {Sep}, pages = {361-372}, doi = {10.3844/jmssp.2012.361.372}, url = {https://thescipub.com/abstract/jmssp.2012.361.372}, abstract = {Problem statement: Due to the long range nature of interactions of the N-body systems, direct computation of the Coulomb potential energy involves O(N2) operations. To decrease such complexity, a simple Multilevel Summation method has been developed. Approach: In the frame of the Multilevel Summation method, the two-body interaction is decomposed into two parts: a local part and a smooth part. The local part vanishes beyond some cut-off distance; hence, its contribution to the potential energy is calculated in O(N) operations. In contrast to some common fast summation methods, the smooth part is calculated in real space on a sequence of grids with increasing meshsize in O(N) operations. Results: The method is tested on the calculation of the Madelung constants of ionic crystals in one, two and three dimensional cases. For a cut-off distance equals three times the meshsize of the ionic crystal, an error less than 0.01% is obtained. Conclusion: In computing the coulomb lattice sums of charge systems consisting of N bodies, the Multilevel Summation method decreases the complexity to O(N) operations.}, journal = {Journal of Mathematics and Statistics}, publisher = {Science Publications} }