Design molecular solid state structures with required properties, use of intermolecular interactions. The 2 main strategies currently in use for crystal engineering are based on hydrogen-bonding and coordination-bonding. Key concepts like supramolecular synthon and the secondary building unit. Crystal engineering bonding to achieve the organization of molecules & ions in the solid state.
Organic systems focused on the use of hydrogen bonds, though with the new extension to inorganic systems. Today CSD having nearly 800 000 crystal structures, this forms heuristic or synthon based or experimental crystal-engineering.