Linear scaling pseudo Fermi-operator expansion for fractional occupation

Journal Article · Mon Nov 19 00:00:00 EST 2018 · Journal of Chemical Theory and Computation

DOI:https://doi.org/10.1021/acs.jctc.8b00887· OSTI ID:1484660

Mniszewski, Susan M. ^[1]; Perriot, Romain ^[1]; Rubensson, Emanuel H. ^[2]; Negre, Christian F. A. ^[1]; Cawkwell, Marc J. ^[1]; Niklasson, Anders M. N. ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Uppsala Univ., Uppsala (Sweden)

Recursive Fermi-operator expansion methods for the calculation of the idempotent density matrix are valid only at zero electronic temperature with integer occupation numbers. We show how such methods can be modified to include fractional occupation numbers of an approximate or pseudo Fermi-Dirac distribution and how the corresponding entropy term of the free energy is calculated. The proposed methodology is demonstrated and evaluated for different electronic structure methods including density functional tight-binding theory, Kohn-Sham density functional theory using numerical orbitals, and quantum chemistry Hartree-Fock theory using Gaussian basis functions.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: 89233218CNA000001
• OSTI ID: 1484660
• Report Number(s): LA-UR-18-28001
• Journal Information: Journal of Chemical Theory and Computation, Vol. 15, Issue 1; ISSN 1549-9618
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Mathematics
molecular dynamics
electronic structure theory
parallel algorithms