Turbo charging time-dependent density-functional theory with Lanczos chains (Articolo in rivista)

Type
Label
  • Turbo charging time-dependent density-functional theory with Lanczos chains (Articolo in rivista) (literal)
Anno
  • 2008-01-01T00:00:00+01:00 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi
  • 10.1063/1.2899649 (literal)
Alternative label
  • Rocca, D; Gebauer, R; Saad, Y; Baroni, S (2008)
    Turbo charging time-dependent density-functional theory with Lanczos chains
    in The Journal of chemical physics
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Rocca, D; Gebauer, R; Saad, Y; Baroni, S (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 128 (literal)
Rivista
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • \"[Rocca, Dario; Baroni, Stefano] Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy; [Rocca, Dario; Gebauer, Ralph; Baroni, Stefano] CNR INFM DEMOCRITOS, Theory Elettra Grp, I-34014 Trieste, Italy; [Gebauer, Ralph] Abdus Salam Int Ctr Theoret Phys, I-34014 Trieste, Italy; [Saad, Yousef] Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA; [Saad, Yousef] Minnesota Supercomp Inst, Minneapolis, MN 55455 USA (literal)
Titolo
  • Turbo charging time-dependent density-functional theory with Lanczos chains (literal)
Abstract
  • We introduce a new implementation of time-dependent density-functional theory which allows the entire spectrum of a molecule or extended system to be computed with a numerical effort comparable to that of a single standard ground-state calculation. This method is particularly well suited for large systems and/or large basis sets, such as plane waves or real-space grids. By using a superoperator formulation of linearized time-dependent density-functional theory, we first represent the dynamical polarizability of an interacting-electron system as an off-diagonal matrix element of the resolvent of the Liouvillian superoperator. One-electron operators and density matrices are treated using a representation borrowed from time-independent density-functional perturbation theory, which permits us to avoid the calculation of unoccupied Kohn-Sham orbitals. The resolvent of the Liouvillian is evaluated through a newly developed algorithm based on the nonsymmetric Lanczos method. Each step of the Lanczos recursion essentially requires twice as many operations as a single step of the iterative diagonalization of the unperturbed Kohn-Sham Hamiltonian. Suitable extrapolation of the Lanczos coefficients allows for a dramatic reduction of the number of Lanczos steps necessary to obtain well converged spectra, bringing such number down to hundreds (or a few thousands, at worst) in typical plane-wave pseudopotential applications. The resulting numerical workload is only a few times larger than that needed by a ground-state Kohn-Sham calculation for a same system. Our method is demonstrated with the calculation of the spectra of benzene, C-60 fullerene, and of chlorophyll a. (C) 2008 American Institute of Physics. (literal)
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