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No arbitrage condition and existence of equilibrium in infinite or finite dimension with expected risk averse utilities
Efficient and accurate calculation of exact exchange and RPA correlation energies in the Adiabatic-Connection Fluctuation-Dissipation theory
Recently there has been a renewed interest in the calculation of
exact-exchange and RPA correlation energies for realistic systems. These
quantities are main ingredients of the so-called EXX/RPA+ scheme which has been
shown to be a promising alternative approach to the standard LDA/GGA DFT for
weakly bound systems where LDA and GGA perform poorly. In this paper, we
present an efficient approach to compute the RPA correlation energy in the
framework of the Adiabatic-Connection Fluctuation-Dissipation formalism. The
method is based on the calculation of a relatively small number of eigenmodes
of RPA dielectric matrix, efficiently computed by iterative density response
calculations in the framework of Density Functional Perturbation Theory. We
will also discuss a careful treatment of the integrable divergence in the
exact-exchange energy calculation which alleviates the problem of its slow
convergence with respect to Brillouin zone sampling. As an illustration of the
method, we show the results of applications to bulk Si, Be dimer and atomic
systems.Comment: 12 pages, 6 figures. To appear in Phys. Rev.
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