ABSTRACT
This chapter introduces the physical chemistry of materials under high pressures. Space limitations permit only a broad-brush introductory survey. High-pressure studies range from designing equipment to generate, to confine and to measure high pressures to spectroscopic studies from 105 Hz to beyond 1019 Hz at temperatures from below 1 K to 105 K and beyond for all sorts of elements, compounds, solutions and mixtures. To say that these are extreme ranges of conditions is an understatement.
