A new real-space algorithm for realistic density functional calculations

We present the implementation of a fast real-space algorithm for density functional calculations for atomic nanoclusters. The numerical method is based on a fourth-order operator splitting technique for the solution of the Kohn-Sham equation [1]. The convergence of the procedure is about one order of magnitude better than that of previously used second-order operator factorizations. The method has now been extended to deal with non-local pseudopotentials of the Kleinman-Bylander [2] type, permitting calculations for realistic systems, without significantly degrading the convergence rate. We demonstrate the convergence of the method for the examples C and C₆₀ and present examples of structure calculations of Na and Mg clusters.