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Title: Crystal structure optimisation using an auxiliary equation of state

Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy–volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other “beyond” density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu{sub 2}ZnSnS{sub 4} and the magnetic metal-organic framework HKUST-1.
Authors:
; ; ;  [1] ;  [1] ;  [2]
  1. Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)
  2. (Korea, Republic of)
Publication Date:
OSTI Identifier:
22493206
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 18; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CRYSTAL STRUCTURE; DEGREES OF FREEDOM; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; EQUATIONS OF STATE; EQUILIBRIUM; LEAD SULFIDES; LEAD TELLURIDES; OPTIMIZATION; ORGANOMETALLIC COMPOUNDS; SEMICONDUCTOR MATERIALS; ZINC SULFIDES; ZINC TELLURIDES