Molecular crystal structure prediction (CSP) aims to predict the set of likely crystal structures of a molecule through computational methods alone, starting from no more than the chemical diagram. The crystal structure adopted by a molecule is important because it affects many properties of materials, including physical and chemical stability , melting points , solubility , morphology , porosity and electronic/optoelectronic properties . The relationship between molecular structure and crystal structure is complicated by the phenomenon of polymorphism, where different crystal structures of the same chemical composition can be accessed experimentally, either concomitantly or under different crystallization conditions. Thus, a given molecule can have very different materials properties, depending on polymorph, and control of crystal structure can be exploited in matters as simple as improving the daily experience of eating chocolate , or as severe as preventing drug ineffectiveness .