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Optimized Effective Potential Method in Current-Spin Density Functional Theory

S. Pittalis·S. Kurth·N. Helbig·E. K. U. Gross
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Abstract

Current-spin density functional theory (CSDFT) provides a framework to describe interacting many-electron systems in a magnetic field which couples to both spin- and orbital-degrees of freedom. Unlike in usual (spin-) density functional theory, approximations to the exchange-correlation energy based on the model of the uniform electron gas face problems in practical applications. In this work, explicitly orbital-dependent functionals are used and a generalization of the Optimized Effective Potential (OEP) method to the CSDFT framework is presented. A simplifying approximation to the resulting integral equations for the exchange-correlation potentials is suggested. A detailed analysis of these equations is carried out for the case of open-shell atoms and numerical results are given using the exact-exchange energy functional. For zero external magnetic field, a small systematic lowering of the total energy for current-carrying states is observed due to the inclusion of the current in the Kohn-Sham scheme. For states without current, CSDFT results coincide with those of spin density functional theory.

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S. Pittalis, S. Kurth, N. Helbig, E. K. U. Gross. 2006-09-27. Optimized Effective Potential Method in Current-Spin Density Functional Theory. https://doi.org/10.1103/physreva.74.062511

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