A simplified methodology for the modeling of interfaces of elementary metals

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 lambda 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} Sigma 5 twist grain boundary, the present algorithm also reproduced gamma-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. (c) 2021 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).

Automated summary

An algorithm is proposed to generate reasonable atomic-level interface models using minimal first-principles calculations. By filtering surface charge densities and selecting models with maximum overlap between slabs, initial models with desirable rigid-body translations are obtained and relaxed to achieve reasonable interface models. This approach successfully generated initial models for various orientations of homointerfaces and reproduced key features of specific grain boundaries. Further modifications are expected to enhance the automated interface model generation process.