Multi-temperature electron density studies

Abstract

This chapter deals with the variation in the electron density distribution of crystalline solids that may occur as a function of temperature (T) changes. The main focus is on experimental electron densities studied by single-crystal X-ray diffraction. In the first part of the chapter, the requirement of temperatures as low as possible for accurate and precise investigations is discussed. Then T-driven physical and chemical changes in the solid state are closely examined. In particular, some test-cases are presented to show how temperature can be used as a variable parameter to explore the correlations between the structural and electronic degrees of freedom in a crystal. Cases of structural phase transitions and electronic spin transitions in molecular crystals are also discussed.