ABSTRACT
INTRODUCTION In addition to the crystallographic techniques of X-ray diffraction and optical crystallography, methodologies based on molecular spectroscopy have become extremely important for the characterization of polymorphs and solvatomorphs (1). These methods become particularly useful when information must be obtained from a small amount of sample in a short period of time, and because most of the methods are non-destructive in nature, the analyzed material can be recycled for additional study once the measurements are complete. A number of techniques have been developed for the characterization of compounds in the solid state, and those based on probing the periodic motion of atoms and groups of atoms in molecules in solids will form the scope of this chapter.
