FUNDAMENTAL MEASURE-THEORY FOR MIXTURES OF PARALLEL HARD CUBES .1. GENERAL FORMALISM

This article, the first of a series of two, describes the formulation of Rosenfeld's fundamental measure theory for a mixture of parallel ha rd cubes, a model recently introduced to study the demixing transition for additive hard core potentials. Special emphasis is put on the goo d performance of the functional when reducing the dimensionality of th e system, a necessary feature to give reasonable results in highly inh omogeneous situations. This property allows for an extremely simple fo rmulation of the theory in arbitrary dimensions. In a subsequent artic le we will describe the properties of the mixture as they are predicte d by the theory, in particular the demixing in presence of the freezin g transition. (C) 1997 American Institute of Physics.