Range separation combined with the Overhauser model: application to the H2 molecule along the dissociation curve

The combination of density-functional theory with other approaches to the many-electron problem through the separation of the electron- electron interaction into a short-range and a long-range contribution (range separation) is a successful strategy, which is raising more and more interest in recent years. We focus here on a range-separated method in which only the short-range correlation energy needs to be approximated, and we model it within the "extended Overhauser approach." We consider the paradigmatic case of the H