an:05078590
Zbl 1105.65111
Zhou, Yunkai; Saad, Yousef; Tiago, Murilo L.; Chelikowsky, James R.
Self-consistent-field calculations using Chebyshev-filtered subspace iteration
EN
J. Comput. Phys. 219, No. 1, 172-184 (2006).
00188124
2006
j
65N25 35P15 35P30
density functional theory; Chebyshev polynomial filter; subspace iteration; eigenproblem; real-space pseudopotential; numerical examples; Kohn-Sham equations; self-consistent-field iteration; eigenvalue; invariant subspace
Summary: The power of density functional theory is often limited by the high computational demand in solving an eigenvalue problem at each self-consistent-field (SCF) iteration. The method presented in this paper replaces the explicit eigenvalue calculations by an approximation of the wanted invariant subspace, obtained with the help of well-selected Chebyshev polynomial filters. In this approach, only the initial SCF iteration requires solving an eigenvalue problem, in order to provide a good initial subspace. In the remaining SCF iterations, no iterative eigensolvers are involved. Instead, Chebyshev polynomials are used to refine the subspace. The subspace iteration at each step is easily five to ten times faster than solving a corresponding eigenproblem by the most efficient eigen-algorithms. Moreover, the subspace iteration reaches self-consistency within roughly the same number of steps as an eigensolver-based approach. This results in a significantly faster SCF iteration.