Accurate kinetic energy evaluation in electronic structure calculations with localised functions on real space grids
نویسندگان
چکیده
We present a method for calculating the kinetic energy of localised functions represented on a regular real space grid. This method uses fast Fourier transforms applied to restricted regions commensurate with the simulation cell and is applicable to grids of any symmetry. In the limit of large systems it scales linearly with system size. Comparison with the finite difference approach shows that our method offers significant improvements in accuracy without loss of efficiency. Published as Computer Physics Communications 140 (2001) 315-322
منابع مشابه
Accurate kinetic energy evaluation in electronic structure calculations with localized functions on real space grids
We present a method for calculating the kinetic energy of localized functions represented on a regular real space grid. This method uses fast Fourier transforms applied to restricted regions commensurate with the simulation cell and is applicable to grids of any symmetry. In the limit of large systems it scales linearly with system size. Comparison with the finite difference approach shows that...
متن کاملComparison of variational real-space representations of the kinetic energy operator
We present a comparison of real-space methods based on regular grids for electronic structure calculations that are designed to have basis set variational properties, using as a reference the conventional method of finite differences ~a real-space method that is not variational! and the reciprocal-space plane-wave method which is fully variational. We find that a definition of the finite-differ...
متن کاملwannier90: A tool for obtaining maximally-localised Wannier functions
We present wannier90, a program for calculating maximally-localised Wannier functions (MLWF) from a set of Bloch energy bands that may or may not be attached to or mixed with other bands. The formalism works by minimising the total spread of the MLWF in real space. This is done in the space of unitary matrices that describe rotations of the Bloch bands at each k-point. As a result, wannier90 is...
متن کاملEmbedded divide-and-conquer algorithm on hierarchical real-space grids: parallel molecular dynamics simulation based on linear-scaling density functional theory
A linear-scaling algorithm has been developed to perform large-scale molecular-dynamics (MD) simulations, in which interatomic forces are computed quantum mechanically in the framework of the density functional theory. A divide-and-conquer algorithm is used to compute the electronic structure, where non-additive contribution to the kinetic energy is included with an embedded cluster scheme. Ele...
متن کاملImplementation of ultrasoft pseudopotentials in large-scale grid-based electronic structure calculations
An implementation of Vanderbilt ultrasoft pseudopotentials in real-space grid-based electronic structure calculations is presented. Efficient utilization of these pseudopotentials requires the use of different grids for i wave functions, ii charge density, and iii sharply peaked operators within the atomic core radii. High-order interpolation between the various grids is important for accuracy,...
متن کامل