Density-matrix functionals from Green's functions | |
Article | |
关键词: MEAN-FIELD THEORY; NATURAL SPIN-ORBITALS; ELECTRONIC-STRUCTURE; INFINITE DIMENSIONS; SYSTEMS; ENERGY; APPROXIMATIONS; INSULATORS; MOLECULES; FERMIONS; | |
DOI : 10.1103/PhysRevB.88.205139 | |
来源: SCIE |
【 摘 要 】
The exact reduced density-matrix functional is derived from the Luttinger-Ward functional of the single-particle Green's function. Thereby, a formal link is provided between diagrammatic many-body approaches using Green's functions on the one hand and theories based on many-body wave functions on the other. This link can be used to explicitly construct approximations for the density-matrix functional that are equivalent to standard diagrammatic resummation techniques and to nonperturbative dynamical mean field theory in particular. Contrary to functionals of the Green's function, the exact density-matrix functional is convex and thus provides a true minimum principle which facilitates the calculation of the grand potential and derived equilibrium properties. The benefits of the proposed Green's-function-based density-matrix functional theory for geometrical structure optimization of strongly correlated materials are discussed.
【 授权许可】
Free