Approximative 'one particle' bridge function B~(1)(r) for the theory of simple fluids

摘要

New properties for the one particle bridge function B~(1)(r), which are necessary to the calculation of the excess chemical potential beta mu_(ex), are derived for the hard sphere fluid. The method, which only requires the knowledge of the bridge function B~(2)(r), is based on an investigation of the correlation function dependence on the Kirkwood charging parameter. In this framework, the unavoidable question of topological homotopy is addressed. As far as B~(2)(r) is considered as exact, this work provides useful information on B~(1)(r) in the well identified dynamical regimes of the hard sphere fluid. Signatures of the transitions between these regimes are identified on the trends of B~(1)(r). This approach provides self-consistent results for beta mu_(ex) that agree very well with simulation data.