Thermodynamic Perturbation Approach to Freezing of the Classical One-Component Plasma

Abstract

Systematic investigations are made of the thermodynamic perturbation approach to freezing, which has proved successful for systems interacting through soft-core or long-ranged potentials. The classical one-component plasma (OCP) is taken as the extreme case of such systems and the investigations focus on the reference systems employed in this approach and on the approximation schemes used to treat that system. It is confirmed that good results are obtained for the freezing properties of the OCP if a system with repulsive, short-ranged potential is properly chosen as the reference system, and both this system and the remaining part due to the long-range interaction are separately treated by the modified weighted-density approximation (MWDA) using accurate input data. However, if we adopt the hard spheres as the reference system in this approach and use either the MWDA or the generalized effective-liquid approximation (GELA) for this system, we cannot get similar results unless we use the input data in the ...