Substrate screening approach for quasiparticle energies of two-dimensional interfaces with lattice mismatch

The authors develop an efficient and accurate interpolation technique for the matrix elements of dielectric matrices in the entire $\mathbf{q}$ + $\mathbf{G}$ reciprocal space between material and substrate.The method makes possible quasiparticle energy calculations within the $G\phantom{\rule{0}{0ex}}W$ approximation for arbitrarily mismatched interfaces, free of strain and symmetry constraints. This is extremely important for practical applications.