Equation of State of Materials

Equation of state (EOS)—a macroscopic representation of the thermodynamic state of materials under static and shock compression, is amongst the most widely studied and used properties of materials under pressure. This chapter primarily deals with the theoretical aspects of obtaining reliable equation of state of materials. While early work used empirical or classical methods, developments of quantum mechanical, density functional theory-based first principle computational procedures are now able to provide not only reliable prediction of the equation of state, but these also help the understanding of the role played by various fundamental changes—such as alterations in the character of electronic states etc. This chapter presents an overview of the field with examples of several materials.