The preconditioning methods for self-consistent iteration of Kohn-Sham density functional theory

发布时间：2018-03-30 来源：赢咖3 浏览次数：

Speaker:	高兴誉	DateTime:	2018年4月13日(周五)上午10:00-11:00
Brief Introduction to Speaker: 高兴誉，北京应用物理与计算数学研究所高性能计算中心，副研究员。		Place:	六号楼二楼报告厅
Abstract:Kohn-Sham density functional theory has been widely used in the first-principles calculations of materials. It is a usual practice to calculate the occupied orbitals for semiconducting, insulating or isolated systems. It differs significantly in metallic systems and partial occupancies have to be included at the same time. In the language of optimization, this is an ill-conditioning problem with partial occupancies treated as additional variational degrees of freedom. We will find the origin of the conditioning problem related to metallic systems and discuss specific strategies for it. An alternative approach is to solve the fixed-point problem generalized from the Kohn-Sham equation by the self-consistent field (SCF) iteration. One reason why the self-consistent schemes are efficient lies probably in the fact that both subproblems can be preconditioned well with plane wave basis.