- Letter
Many-body energy density functional
Phys. Rev. A 104, L030801 – Published 20 September, 2021
DOI: https://doi.org/10.1103/PhysRevA.104.L030801
Abstract
The Hohenberg-Kohn theorem and the Kohn-Sham equations, which are at the basis of the density-functional theory, are reformulated in terms of a particular many-body density, which is translational and Galilean invariant and therefore is relevant for self-bound systems. In a similar way that there is a unique relation between the one-body density and the external potential that gives rise to it, we demonstrate that there is a unique relation between that particular many-body density and a definite many-body potential. The energy is then a functional of this density, and its minimization leads to the ground-state energy of the system. As a proof of principle, the analogous of the Kohn-Sham equation is solved in the specific case of atomic clusters, to put in evidence the advantages of this formulation in terms of physical insights.