Get access

Implementation of the diagonalization-free algorithm in the self-consistent field procedure within the four-component relativistic scheme

Authors

  • Marcela Hrdá,

    1. Department of Theoretical Chemistry, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
    Search for more papers by this author
  • Tomáš Kulich,

    1. Department of Computer Science, Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
    Search for more papers by this author
  • Michal Repiský,

    1. Department of Theoretical Chemistry, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
    2. Department of Chemistry, The Centre for Theoretical and Computational Chemistry (CTCC), UiT, The Arctic University of Norway, Tromsø, Norway
    Search for more papers by this author
  • Jozef Noga,

    1. Department of Theoretical Chemistry, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
    2. Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
    3. Computing Centre, Slovak Academy of Sciences, Bratislava, Slovakia
    Search for more papers by this author
  • Olga L. Malkina,

    Corresponding author
    1. Department of Theoretical Chemistry, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
    2. Department of Inorganic Chemistry, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
    Search for more papers by this author
  • Vladimir G. Malkin

    1. Department of Theoretical Chemistry, Institute of Inorganic Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
    Search for more papers by this author

Abstract

A recently developed Thouless-expansion-based diagonalization-free approach for improving the efficiency of self-consistent field (SCF) methods (Noga and Šimunek, J. Chem. Theory Comput. 2010, 6, 2706) has been adapted to the four-component relativistic scheme and implemented within the program package ReSpect. In addition to the implementation, the method has been thoroughly analyzed, particularly with respect to cases for which it is difficult or computationally expensive to find a good initial guess. Based on this analysis, several modifications of the original algorithm, refining its stability and efficiency, are proposed. To demonstrate the robustness and efficiency of the improved algorithm, we present the results of four-component diagonalization-free SCF calculations on several heavy-metal complexes, the largest of which contains more than 80 atoms (about 6000 4-spinor basis functions). The diagonalization-free procedure is about twice as fast as the corresponding diagonalization. © 2014 Wiley Periodicals, Inc.

Ancillary