A spectral scheme for Kohn–Sham density functional theory of clusters

Journal Article · Wed Apr 15 04:00:00 EDT 2015 · Journal of Computational Physics

DOI:https://doi.org/10.1016/J.JCP.2015.02.009· OSTI ID:22465621

Starting from the observation that one of the most successful methods for solving the Kohn–Sham equations for periodic systems – the plane-wave method – is a spectral method based on eigenfunction expansion, we formulate a spectral method designed towards solving the Kohn–Sham equations for clusters. This allows for efficient calculation of the electronic structure of clusters (and molecules) with high accuracy and systematic convergence properties without the need for any artificial periodicity. The basis functions in this method form a complete orthonormal set and are expressible in terms of spherical harmonics and spherical Bessel functions. Computation of the occupied eigenstates of the discretized Kohn–Sham Hamiltonian is carried out using a combination of preconditioned block eigensolvers and Chebyshev polynomial filter accelerated subspace iterations. Several algorithmic and computational aspects of the method, including computation of the electrostatics terms and parallelization are discussed. We have implemented these methods and algorithms into an efficient and reliable package called ClusterES (Cluster Electronic Structure). A variety of benchmark calculations employing local and non-local pseudopotentials are carried out using our package and the results are compared to the literature. Convergence properties of the basis set are discussed through numerical examples. Computations involving large systems that contain thousands of electrons are demonstrated to highlight the efficacy of our methodology. The use of our method to study clusters with arbitrary point group symmetries is briefly discussed.

• OSTI ID: 22465621
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Vol. 287; ISSN JCTPAH; ISSN 0021-9991
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCURACY
ALGORITHMS
ATOMIC CLUSTERS
BENCHMARKS
BESSEL FUNCTIONS
CONVERGENCE
DENSITY FUNCTIONAL METHOD
EIGENFUNCTIONS
EIGENSTATES
ELECTRONIC STRUCTURE
ELECTROSTATICS
EQUATIONS
HAMILTONIANS
MOLECULES
PERIODIC SYSTEM
POLYNOMIALS
POTENTIALS
SPHERICAL HARMONICS
WAVE PROPAGATION