Using the Bond Valence Sum Model to calculate Li-diffusion pathways in Silicene with MgX2 (X=Cl, Br, I) substrates

Abstract

Using the BVS method, we calculate Li-ion pathways and diffusion barriers in the interface between silicene and MgCl2, MgBr2 and MgI2 substrates and we show that the results are in good agreement with the previously published DFT studies. In addition, we showcase that BVS does not need the exact crystal structure as we examine different initial positions for the Li ion and different interface heights without affecting the calculated BVSE . Furthermore, we show that surface diffusion BVS calculations can be used to roughly optimize the interface, thus completely foregoing DFT geometry optimization calculations. Here, we propose that BVS can substitute DFT as a quick filter when searching for low migration barriers in silicene-based materials, providing good enough accuracy.