What is "cocrystal"

n. (context organic chemistry English) A crystal, often a large-molecule crystal, having two or more distinct molecular components within the crystal lattice.

The definition of a cocrystal has been debated in the crystallography field. This definition can encompass many types of compounds, including hydrates, solvates and clathrates, which represent the basic principle of host-guest chemistry. Hundreds of examples of cocrystallization are reported annually.

Although the exact definition of a cocrystal remains topic of debate, most solid-state chemists agree nowadays that they can be defined as “solids that are crystalline single phase materials composed of two or more different molecular and/or ionic compounds generally in a stoichiometric ratio which are neither solvates nor simple salts.” Several subclassifications exist.