Conventional methods for atomistic simulations based on density-functional theory (DFT), such as the plane-wave pseudopotential approach, have had an immense impact on the way in which material properties are studied. In spite of this success, the system-size accessible to such techniques is limited because the algorithms scale with the cube of the number of atoms. The quest to bring to bear the predictive power of DFT calculations on ever larger systems has resulted in much recent interest in linear scaling methods for DFT simulations. The plane-waves of conventional DFT calculations have many desirable properties, not least of which is the ability to systematically control basis set completeness, and hence the accuracy of one’s calculation, with a single parameter. The extended nature of plane-waves, however, would appear to make them unsuitable for describing the real-space localised orbitals used in linear scaling methods. In spite of this, we have developed ONETEP (Order-N Total Energy Package), a linear scaling method based on a plane-wave basis set, which overcomes the above difficulty and which is able to achieve the same accuracy and convergence rate as the conventional plane-wave approach. The novel features of our method which result in its success will be described and results for realistic applications from the ONETEP parallel code will be presented.
Journal: TechConnect Briefs
Volume: 1, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 1
Published: May 7, 2006
Pages: 633 - 636
Industry sector: Advanced Materials & Manufacturing
Topic: Informatics, Modeling & Simulation