Journal article
A General Approach for Reducing Continuous Translational Symmetry Errors in Finite Difference Real-Space Calculations
Journal of Chemical Theory and Computation, Vol.16(7)
14/Jul/2020
Abstract
We provide a new scheme for representing pseudopotentials on a finite real-space grid, designed to significantly reduce the "egg box'' effect, i.e., unphysical fluctuations of computed quantities upon real-space translation. Instead of interpolating the electron-ion potential onto the grid, our scheme starts at a reference position and then uses a weighted sum of translation operators to account for the positions of atoms in real space. This results in a nonlocal but banded representation (even for local potentials) which is fully compatible with nonlocal pseudopotential operators. As a demonstration, this scheme is tested in one dimension for three types of potentials: a local pseudopotential, a nonlocal pseudopotential, and a local pseudopotential with self-consistent Hartree and exchange-correlation potentials. This scheme is found to reduce fluctuations of examined quantities by at least three orders of magnitude. The approach requires neither grid adaptation nor pseudopotential modification and can be readily extended to the three-dimensional case.
Details
- Title
- A General Approach for Reducing Continuous Translational Symmetry Errors in Finite Difference Real-Space Calculations
- Creators
- Tian Qiu (null) - University of PennsylvaniaLeeor Kronik (null) - The Weizmann Institute of ScienceAndrew M. Rappe (Corresponding Author) - University of Pennsylvania
- Resource Type
- Journal article
- Publication Details
- Journal of Chemical Theory and Computation, Vol.16(7); 14/Jul/2020
- Number of pages
- 10
- Language
- English
- DOI
- https://doi.org/10.1021/acs.jctc.0c00238
- Grant note
- We thank Dr. Liang Tan (Lawrence Berkeley National Laboratory) for helpful discussions. T.Q. conceived the “shift operator” idea, derived the theoretical model, performed the numerical simulations, and produced all figures and tables under the support from the Vagelos Institute for Energy Science and Technology (VIEST). L.K. participated in the shaping of the idea, derivation of the model, and discussions on the numerical results as the incumbent of the Aryeh and Mintzi Katzmann Professorial Chair. A.M.R initiated the project, participated in the shaping of the idea, derivation of the model, and discussions on the numerical results under the support from the Department of Energy under grant DE-FG02-07ER46431. All authors actively participated in the drafting of the manuscript. The authors also acknowledge computational support from the High-Performance Computing Modernization Office and the National Energy Research Scientific Computing Center.
- Record Identifier
- 993266973403596
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