title: Classical density functional theory and the phase-field crystal method using a rational function to describe the two-body direct correlation function.
abstract: We introduce a new approach to represent a two-body direct correlation function (DCF) in order to alleviate the computational demand of classical density functional theory (CDFT) and enhance the predictive capability of the phase-field crystal (PFC) method. The approach utilizes a rational function fit (RFF) to approximate the two-body DCF in Fourier space. We use the RFF to show that short-wavelength contributions of the two-body DCF play an important role in determining the thermodynamic properties of materials. We further show that using the RFF to empirically parametrize the two-body DCF allows us to obtain the thermodynamic properties of solids and liquids that agree with the results of CDFT simulations with the full two-body DCF without incurring significant computational costs. In addition, the RFF can also be used to improve the representation of the two-body DCF in the PFC method. Last, the RFF allows for a real-space reformulation of the CDFT and PFC method, which enables descriptions of nonperiodic systems and the use of nonuniform and adaptive grids.
authors: Materials Science and Engineering Department, University of Michigan, Ann Arbor, Michigan 48109, USA. nirand@umich.edu
authors: N
authors: N
authors: Pisutha-Arnond
authors: V W L
authors: VW
authors: Chan
authors: M
authors: M
authors: Iyer
authors: V
authors: V
authors: Gavini
authors: K
authors: K
authors: Thornton
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003461:Crystallography / Q000379:methods*; D008962:Models, Theoretical; D009716:Numerical Analysis, Computer-Assisted; D011789:Quantum Theory; D013223:Statistics as Topic; D013816:Thermodynamics