×

Preconditioning systems arising from the KKR Green function method using block-circulant matrices. (English) Zbl 1231.65063

Summary: Recently, a linearly scaling method for the calculation of the electronic structure based on the Korringa-Kohn-Rostoker Green function method has been proposed. The method uses the transpose free quasi minimal residual method (TFQMR) to solve linear systems with multiple right hand sides. These linear systems depend on the energy-level under consideration and the convergence rate deteriorates for some of these energy points. While traditional preconditioners like ILU are fairly useful for the problem, the computation of the preconditioner itself is often relatively hard to parallelize. To overcome these difficulties, we develop a new preconditioner that exploits the strong structure of the underlying systems. The resulting preconditioner is block-circulant and thus easy to compute, invert and parallelize. The resulting method yields a dramatic speedup of the computation compared to the unpreconditioned solver, especially for critical energy levels.

MSC:

65F08 Preconditioners for iterative methods
15B05 Toeplitz, Cauchy, and related matrices
Full Text: DOI

References:

[1] Zeller, R., Towards a linear-scaling algorithm for electronic structure calculations with the tight-binding Korringa-Kohn-Rostoker Green function method, J. Phys.: Condens. Matter, 20, 294215 (2008)
[2] Freund, R. W., A transpose-free quasi-minimal residual algorithm for non-hermitian linear systems, SIAM J. Sci. Comput., 14, 2, 470-482 (1993) · Zbl 0781.65022
[3] R. Gray, Toeplitz and circulant matrices: a review, Tech. Rep. 6504-1, Stanford University, Stanford, CA, 1977.; R. Gray, Toeplitz and circulant matrices: a review, Tech. Rep. 6504-1, Stanford University, Stanford, CA, 1977.
[4] Ng, M. K., Iterative Methods for Toeplitz Systems (2004), Oxford University Press: Oxford University Press Oxford · Zbl 1059.65031
[5] Chan, R. H.; Chan, T. F., Circulant preconditioners for elliptic problems, J. Numer. Linear Algebra Appl., 1, 1, 77-101 (1992)
[6] Saad, Y., Iterative Methods for Sparse Linear Systems (2003), SIAM: SIAM Philadelphia · Zbl 1002.65042
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.