Jackson Adam J, Skelton Jonathan M, Hendon Christopher H, Butler Keith T, Walsh Aron
Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
J Chem Phys. 2015 Nov 14;143(18):184101. doi: 10.1063/1.4934716.
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.
局部晶体结构优化的标准程序涉及大量的能量和力的计算。计算能量-体积曲线，围绕平衡晶胞体积拟合状态方程是很常见的。这是一个计算密集型过程，特别是对于低对称性晶体结构，其中每个等容优化都涉及在多个自由度上的能量最小化。对于非局部交换相关泛函或其他“超越”密度泛函理论的电子结构技术，这样的程序可能是禁止的，特别是在没有解析梯度的情况下。我们提出了一种基于已知状态方程的高效晶体结构优化的简单方法。平衡体积可以通过一次单点计算预测出来，如果需要，可以通过连续计算进行细化。该方法使用九种密度泛函对PbS、PbTe、ZnS和ZnTe进行了验证，并应用于四元半导体Cu2ZnSnS4和磁性金属有机框架HKUST-1。
