Equations of state for solids under strong compression

The historical and theoretical background for the different mathematical fo rms commonly used to represent equations of state (EOS) for solids is revie wed and some criteria are discussed which allow to select some specific for ms, which are not only convenient mathematical forms but bring out the phys ical meaning of the data. Some examples are discussed with emphasis on rece nt experimental and theoretical data including noble gas solids, simple met als and a few metals with special "anomalies" to illustrate the differences involved in the use of different EOS forms and to point out the specific p hysical reasons for differences in specific EOS forms.