A many-electron perturbation theory study of the hexagonal boron nitride bilayer system*

Abstract

In this article we explore methods to reduce the computational cost in many-electron wave function expansions including explicit correlation and compact one-electron basis sets for the virtual orbitals. These methods are applied to the calculation of the interlayer binding energy of the h-BN bilayer system. We summarize the optimized interlayer distances as well as their binding energies for various stacking faults on different levels of theory including second-order Møller-Plesset perturbation theory and the random phase approximation. Furthermore, we investigate the asymptotic behavior of the binding energy at large interlayer separation and find that it decays as D-4 in agreement with theoretical predictions, where D is the interlayer distance.