An Analysis of the Critical Region of Multiparameter Equations of State

Abstract In this work, two classes of defects with multiparameter equations of state are investigated. In the first, it is shown that the critical point provided by equation of state developers often does not exactly meet the criticality conditions based upon the first two density derivatives of the pressure being zero at the critical point. Based upon the more accurate locations of the critical points given in the first part, the scaling of the densities along the binodal and spinodal in the critical region are investigated, and we find that the vast majority of equations have reasonable behavior but a few do not.