The goal of this work is to build an object-oriented code that couples single-scale computational models from the microscopic to the mesoscopic to the macroscopic based on density functional theory. S/PHI/nX is a plane-wave code written in C++, which (i) utilizes a matrix-based formulation of density-functional theory and (ii) is completely object-oriented and modular. The matrix-based notation provides an efficient tool to describe new algorithms and gives direct access to fast BLAS3 (matrix-matrix) routines which are significantly faster than single-element or vector operations on modern computer architectures. The high level of modularity makes it easy for beginners to understand, modify and test parts of the code without affecting the rest of the program. The code runs on SuSE Linux Professional 9.3, Apple Mac OS X 10.4, and Windows XP systems. Free download is available to registered users.

Citation: "the pseudopotential plane-wave code S/PHI/nX - ab-initio based multiscale library," Algorithm Design and Modeling Group, Computational Materials Design Department, Max-Planck-Institut für Eisenforschung. Last updated 15-03-06.

Recommendations from the site:
Before starting using S/PHI/nX for the first time we strongly recommend to study the following papers thoroughly:

* Iterative minimization techniques for ab-initio total-energy calculations: molecular dynamics and conjugate-gradients
M.C.Payne, M.P.Teter, D.C.Allan, T.A.Arias, J.D.Joannopoulos, Rev.Mod.Phys. 64, 1045-1097 (1992)

This rather detailed review paper gives a good starting point to understand the basic concepts of DFT calculations.

* Density-functional theory calculations for poly-atomic systems: electronic structure, static and elastic properties and ab initio molecular dynamics
M. Bockstedte, A. Kley, J. Neugebauer, M. Scheffler, Comput. Phys. Commun. 107, 187-222 (1997)

This article is deticated to S/PHI/nX's predessor code fhi98md. It is explained how a pseudopotential-planewave code generally works.

* Ab initio pseudopotentials for electronic structure calculations of poly-atomic systems using density-functional theory.
M. Fuchs, M. Scheffler, Comput. Phys. Commun. 119, 67-98 (1999).

Learn how pseudopotentials can be generated.

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Also see entry FHI98md