  Predicting and characterizing the crystal structure of materials is a key
problem in materials research and development. It is typically addressed with
highly accurate quantum mechanical computations on a small set of candidate
structures, or with empirical rules that have been extracted from a large
amount of experimental information, but have limited predictive power. In this
letter, we transfer the concept of heuristic rule extraction to a large library
of ab-initio calculated information, and demonstrate that this can be developed
into a tool for crystal structure prediction.
