Lower Bounds for Correlation Energy of Mixtures of Charged Hard Spheres

A method to obtain exact lower bounds for the correlation energy of one-component plasmas is extended to neutral mixtures of charged hard spheres. Upper bounds for the correlation functions of charge densities are derived. These upper bounds, the semi-positivity of correlation functions, and that of the charge-densityfluctuation spectrum are used to improve upon the known bound due to Onsager.