Reliable methods of predicting the crystal structure of a compound, based only on its composition, has been a goal of the physical sciences since the 1950s.
[1] Computational methods employed include simulated annealing, evolutionary algorithms, distributed multipole analysis, random sampling, basin-hopping, data mining, density functional theory and molecular mechanics.
Predicting organic crystal structures is important in academic and industrial science, particularly for pharmaceuticals and pigments, where understanding polymorphism is beneficial.
[8] The crystal structures of molecular substances, particularly organic compounds, are very hard to predict and rank in order of stability.
[14][15] The following codes can predict stable and metastable structures given chemical composition and external conditions (pressure, temperature):