title: Parallel self-consistent-field calculations via Chebyshev-filtered subspace acceleration.
abstract: Solving the Kohn-Sham eigenvalue problem constitutes the most computationally expensive part in self-consistent density functional theory (DFT) calculations. In a previous paper, we have proposed a nonlinear Chebyshev-filtered subspace iteration method, which avoids computing explicit eigenvectors except at the first self-consistent-field (SCF) iteration. The method may be viewed as an approach to solve the original nonlinear Kohn-Sham equation by a nonlinear subspace iteration technique, without emphasizing the intermediate linearized Kohn-Sham eigenvalue problems. It reaches self-consistency within a similar number of SCF iterations as eigensolver-based approaches. However, replacing the standard diagonalization at each SCF iteration by a Chebyshev subspace filtering step results in a significant speedup over methods based on standard diagonalization. Here, we discuss an approach for implementing this method in multi-processor, parallel environment. Numerical results are presented to show that the method enables to perform a class of highly challenging DFT calculations that were not feasible before.
authors.affiliation: Department of Mathematics, Southern Methodist University, Dallas, Texas 75275, USA. yzhou@smu.edu
authors.forename: Yunkai
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yousef
authors.initials: Y
authors.lastname: Saad
authors.forename: Murilo L
authors.initials: ML
authors.lastname: Tiago
authors.forename: James R
authors.initials: JR
authors.lastname: Chelikowsky