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 Cu2ZnSnS4 and the magnetic metal-organic framework HKUST-1.
Bibliographical noteFunding Information:
The authors thank J. M. Frost for useful discussions. We acknowledge our use of the ARCHER computing facility through our membership of the UK’s HPC Materials Chemistry Consortium, which is funded by EPSRC Grant No. EP/L000202. J.M.S. is funded by an EPSRC Programme Grant (No. EP/K004956/1). A.J.J. is funded by the EPSRC Doctoral Training Centre in Sustainable Chemical Technologies (Grant Nos. EP/G03768X/1 and EP/L016354/1). A.W. acknowledges support from the Royal Society and the ERC (Grant No. 277757).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry