Twister: Construction and structural relaxation of commensurate moiré superlattices

Abstract

Introduction of a twist between layers of two-dimensional materials which leads to the formation of a moiré pattern is an emerging pathway to tune the electronic, vibrational and optical properties. The fascinating properties of these systems are often linked to large-scale structural reconstruction of the moiré pattern. Hence, an essential first step in the theoretical study of these systems is the construction and structural relaxation of the atoms in the moiré superlattice. We present the Twister package, a collection of tools that constructs commensurate superlattices for any combination of 2D materials and also helps perform structural relaxations of the moiré superlattice. Twister constructs commensurate moiré superlattices using the coincidence lattice method and provides an interface to perform structural relaxations using classical forcefields.