A parallel code for a self-consistent charge density functional based tight binding method: Total energy calculations for extended systems

Abstract

We present a parallel version of a selfconsistent-charge density-functional based tight-binding (SCC-DFTB) method for total energy calculations and geometry optimizations of clusters and periodic structures. On single processor machines the SCC-DFTB method has been successfully applied to systems up to several hundred atoms with an accuracy comparable to sophisticated selfconsistent field density-functional theory (SCF-DFT) methods. The new parallel code allows to treat systems which are larger by an order of magnitude in reasonable time. The freely available ScaLAPACK and PBLAS libraries are used for linear algebra operations. We tested the scaling of our program for a realistic system (III–V semiconductor surface) with different sizes and give a short outlook on current applications.