{ "id": "cond-mat/0104390", "version": "v1", "published": "2001-04-20T12:44:48.000Z", "updated": "2001-04-20T12:44:48.000Z", "title": "The density functional theory of classical fluids revisited", "authors": [ "J. -M. Caillol" ], "comment": "10 pages", "doi": "10.1088/0305-4470/35/19/301", "categories": [ "cond-mat.stat-mech" ], "abstract": "We reconsider the density functional theory of nonuniform classical fluids from the point of view of convex analysis. From the observation that the logarithm of the grand-partition function $\\log \\Xi [\\phi]$ is a convex functional of the external potential $\\phi$ it is shown that the Kohn-Sham free energy ${\\cal A}[\\rho]$ is a convex functional of the density $\\rho$. $\\log \\Xi [\\phi]$ and ${\\cal A}[\\rho]$ constitute a pair of Legendre transforms and each of these functionals can therefore be obtained as the solution of a variational principle. The convexity ensures the unicity of the solution in both cases. The variational principle which gives $\\log \\Xi [\\phi]$ as the maximum of a functional of $\\rho$ is precisely that considered in the density functional theory while the dual principle, which gives ${\\cal A}[\\rho]$ as the maximum of a functional of $\\phi$ seems to be a new result.", "revisions": [ { "version": "v1", "updated": "2001-04-20T12:44:48.000Z" } ], "analyses": { "keywords": [ "density functional theory", "classical fluids", "convex functional", "variational principle", "kohn-sham free energy" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }