1Theory of Condensed Matter group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave, Cambridge CB3 0HE, UK
2Physical & Theoretical Chemistry Laboratory, South Parks Road, University of Oxford, Oxford OX1 3QZ, UK
3Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge MA, USA
An overview of the ONETEP (Order-N Electronic Total Energy Package) code is presented, focusing on the twin aims of overall linear scaling and controlled accuracy. The method is outlined, including a description of the density-matrix formulation of density-functional theory, and the optimisation procedures for both the density-kernel and the local orbitals or non-orthogonal generalised Wannier functions. Results of applying the method to a variety of systems are presented to demonstrate the accomplishment of the original aims.