A new equation of state is obtained in this project by combining the group contribution and equation of state methods for describing polar substances. Group interaction parameters in the new equation are determined for groups of common occurrence so that the equation describes large classes of polar substances and their mixtures. In this project, the success of the group contribution method is extended from the liquid to the entire fluid state. A previous investigation of local composition is continuing. The result will be made part of the new equation of state.
