A hard particle packing algorithm for modeling layered mosaic perovskite alloy microstructures across length scales

Layered metal-halide perovskite materials (general formula A_2 B X_4) display a wide-variety of microstructures that span the order-disorder spectrum and can be tuned via the composition of their constituent B-site octahedral species. To better understand the formation and physical properties of these complex alloys, we develop a computationally efficient hard-particle packing algorithm that models accurately their geometrical and topological properties across length scales. Our algorithm can accurately predict the miscibility of a prescribed composition of different B-site octahedra. Additionally, by identifying the percolating networks of paramagnetic B-site octahedra at various compositions, the simulated structures provide insight into the long-range magnetic order of certain alloys.