Regular Article

Finite element density functional calculations for light molecules using a cusp factor to mitigate the Coulomb potential

¹ Department of Physics, University of South Africa, P.O. Box 392, 0003 UNISA, Pretoria, South Africa
² HySA Infrastructure Centre of Competence, Faculty of Engineering, North-West University (NWU), Potchefstroom 2531, South Africa

^a e-mail: moritz.braun@gmail.com

Received: 12 June 2019
Received in final form: 19 August 2019
Published online: 8 October 2019

Abstract

Finite element calculations have been performed in Cartesian coordinates using the density functional approach for a number of small molecules. In order to aid convergence of the orbitals and total energies a suitable cusp factor was employed, such that the resulting effective potential is non-singular at all nuclei. The resulting total energies and densities were compared with those obtained using the Gaussian basis set package NWChem [M. Valiev et al., Comput. Phys. Commun. 181, 1477 (2010)] and excellent agreement was found.