Abstract
A formalism for the evaluation of zero-field splitting tensors using Kohn-Sham orbitals obtained from periodic density functional calculations is presented. Details for calculations involving all occupied states and integration over the Brillouin zone are included. Numerically intensive and difficult six-dimensional integration in real space is avoided by calculating all quantities in reciprocal space, leading to a considerably more efficient and stable scheme. © 2008 The American Physical Society.