{ "id": "cond-mat/0411625", "version": "v3", "published": "2004-11-25T06:03:00.000Z", "updated": "2007-07-24T04:38:31.000Z", "title": "Maximum Entropy and the Variational Method in Statistical Mechanics: an Application to Simple Fluids", "authors": [ "Chih-Yuan Tseng", "Ariel Caticha" ], "comment": "5 figures. Additional demonstrations on radial distribution functions and equation of states are added", "categories": [ "cond-mat.stat-mech" ], "abstract": "We develop the method of Maximum Entropy (ME) as a technique to generate approximations to probability distributions. The central results consist in (a) justifying the use of relative entropy as the uniquely natural criterion to select a \"best\" approximation from within a family of trial distributions, and (b) to quantify the extent to which non-optimal trial distributions are ruled out. The Bogoliuvob variational method is shown to be included as a special case. As an illustration we apply our method to simple fluids. In a first use of the ME method the \"exact\" canonical distribution is approximated by that of a fluid of hard spheres and ME is used to select the optimal value of the hard-sphere diameter. A second, more refined application of the ME method approximates the \"exact\" distribution by a suitably weighed average over different hard-sphere diameters and leads to a considerable improvement in accounting for the soft-core nature of the interatomic potential. As a specific example, the radial distribution function and the equation of state for a Lennard-Jones fluid (Argon) are compared with results from molecular dynamics simulations.", "revisions": [ { "version": "v3", "updated": "2007-07-24T04:38:31.000Z" } ], "analyses": { "keywords": [ "maximum entropy", "simple fluids", "statistical mechanics", "application", "hard-sphere diameter" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004cond.mat.11625T" } } }