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

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