Study of interplanar binding in graphite by extended Thomas-Fermi theory

Abstract

A model of a graphite crystal is used which consists of a set of parallel slabs of positive charge immersed in an electron sea. Each slab, about 1 Å wide, contains the charge of the nucleus and five electrons per carbon atom, homogeneously distributed in the volume of the slabs. The electron density in the region between slabs is calculated from Thomas-Fermi-Dirac theory including corrections for inhomogeneity to the kinetic energy and correlation energy. Also, a calculation is reported with the electron density obtained by a minimization of the Thomas-Fermi-Dirac-Kirzhnits functional. The results are in semiquantitative agreement with empirical data.