Journal of Chemical Physics 133, 114111 (2010)

Linear-scaling density-functional simulations of charged point defects in Al₂O₃ using hierarchical sparse matrix algebra

N. D. M. Hine¹, P. D. Haynes¹, A. A. Mostofi¹ and M. C. Payne²

¹Department of Physics and Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
²Theory of Condensed Matter Group, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom

We present calculations of formation energies of defects in an ionic solid (Al₂O₃) extrapolated to the dilute limit, corresponding to a simulation cell of infinite size. The large-scale calculations required for this extrapolation are enabled by developments in the approach to parallel sparse matrix algebra operations, which are central to linear-scaling density-functional theory calculations. The computational cost of manipulating sparse matrices, whose sizes are determined by the large number of basis functions present, is greatly improved with this new approach. We present details of the sparse algebra scheme implemented in the ONETEP code using hierarchical sparsity patterns, and demonstrate its use in calculations on a wide range of systems, involving thousands of atoms on hundreds to thousands of parallel processes.

Last updated: 20 September 2010

Linear-scaling density-functional simulations of charged point defects in Al2O3 using hierarchical sparse matrix algebra

Linear-scaling density-functional simulations of charged point defects in Al₂O₃ using hierarchical sparse matrix algebra