A simplified methodology for the modeling of interfaces of elementary metals

Abstract

Automated generation of reasonable atomic-level interface models, for example, at a grain boundary, is generally computationally intensive partly because of the three degrees of freedom in a rigid-body translation (RBT) of one side of the interface against the other. We propose an algorithm to obtain reasonable interface models using as few first-principles calculations as possible. The valence charge densities of two surface slabs constituting the interface are calculated using first-principles calculations. The surface charge densities are filtered with an exponential function using a parameter λ to obtain the reaction front. Models where the overlap of filtered charge densities between the two slabs takes a local maximum are adopted as initial models with desirable RBTs, which are then relaxed using first-principles calculations to obtain a reasonable interface model. The proposed algorithm successfully generated reasonable initial models for three out of three orientations in 75% of homointerfaces of body-centered cubic, face-centered cubic, and hexagonal close-packed non-magnetic elementary metals. For the Al {001} Σ5 twist grain boundary, the present algorithm also reproduced γ-surface features of RBTs showing correct displacement shift complete lattice periodicity. Further modifications and improvements to this method are expected to accelerate automated interface model generation from a previously unexplored approach.