Generating relativistic pseudo-potentials with explicit incorporation of semi-core states using APE, the Atomic Pseudo-potentials Engine

Abstract

We present a computer package designed to generate and test norm-conserving pseudo-potentials within Density Functional Theory. The generated pseudo-potentials can be either non-relativistic, scalar relativistic or fully relativistic and can explicitly include semi-core states. A wide range of exchange–correlation functionals is included. Program summary Program title: Atomic Pseudo-potentials Engine (APE) Catalogue identifier: AEAC_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEAC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 88 287 No. of bytes in distributed program, including test data, etc.: 649 959 Distribution format: tar.gz Programming language: Fortran 90, C Computer: any computer architecture, running any flavor of UNIX Operating system: GNU/Linux RAM: <5 Mb Classification: 7.3 External routines: GSL ( http://www.gnu.org/software/gsl/) Nature of problem: Determination of atomic eigenvalues and wave-functions using relativistic and nonrelativistic Density-Functional Theory. Construction of pseudo-potentials for use in ab-initio simulations. Solution method: Grid-based integration of the Kohn–Sham equations. Restrictions: Relativistic spin-polarized calculations are not possible. The set of exchange–correlation functionals implemented in the code does not include orbital-dependent functionals. Unusual features: The program creates pseudo-potential files suitable for the most widely used ab-initio packages and, besides the standard non-relativistic Hamann and Troullier–Martins potentials, it can generate pseudo-potentials using the relativistic and semi-core extensions to the Troullier–Martins scheme. APE also has a very sophisticated and user-friendly input system. Running time: The example given in this paper (Si) takes 10 s to run on a Pentium IV machine clocked at 2 GHz.