Abstract
A procedure for solving Poisson's equation using plane waves in adaptive coordinates is described. The method, based on Gygi's work, writes a trial potential as the product of a preselected Coulomb weight times a plane-wave expansion depending on . Then, the Coulomb potential generated by a given density is obtained by variationally optimizing , so that the error in the Coulomb energy is second-order with respect to the error in . The Coulomb weight is chosen to provide to each the typical long-range tail of a Coulomb potential, so that calculations on atoms and molecules are made possible without having to resort to the supercell approximation. As a proof of concept, the method is tested on the helium atom and the and molecules, where Hartree-Fock energies with better than milli-Hartree accuracy require only a moderate number of plane waves.
- Received 30 May 2014
DOI:https://doi.org/10.1103/PhysRevE.90.053307
©2014 American Physical Society