Predicting crystal structures

UK researchers have predicted the crystal structures of small organic molecules by computational methods without experimental input - a goal that has been described as the Holy Grail of crystallography.

The breakthrough was achieved in the 4th blind test of crystal structure prediction, an exercise conducted by an international group of fifteen research groups that was organised by the Cambridge Crystallographic Data Centre (CCDC) and Cambridge University.

Crystal structures describe the periodically repeating arrangement of molecules in a material and determine many of a material's properties, such as solubility, dissolution rate, hardness, colour and external shape. The ability to predict crystal structures could thus revolutionise the design of materials with novel properties.

In particular, the pharmaceutical industry would gain huge benefit from reliable methods of crystal structure prediction because pharmaceutical molecules are prone to crystallise in more than one crystal structure (or polymorph), depending on the conditions under which the molecule is crystallised. The specific polymorph that goes into a formulation must be strictly controlled to ensure consistency of delivery to the patient.