Organic crystals: engineering and design

Supramolecular synthons have been defined as the basic molecular entities which recognize each other in a predictable manner for the formation of crystalline assemblies; statistical studies of recognition modes have been mainly concerned with hydrogen bonding. In the classical approach, quantum chemical and parametric methods have been employed to calculate relative lattice energies in an attempted ab initio crystal structure prediction. Supersonic nozzle expansion, with electron diffraction and molecular dynamics calculations on the resulting clusters, are leading the way to understanding nucleation and phase transition phenomena. Molecular dynamic studies of crystal precursors in solution are a promising pathway to understanding crystal genesis.