Searching for Potential Structures

The prediction of crystal structures involves the identifieation of minima on the potential energy landscape, regardless of the method used to calculate this landscape. Owing to the many degrees of freedom involved, this process is not trivial, in particular for co-crystals and salts. This section provides an overview of search methods used in crystal structure prediction and the most important pitfalls are discussed. 

The simplest form of conformational search is a grid scan. Here each degree of freedom is explored in turn over a range of values which systematically samples that variable. The energies of the molecule at all geometries are calculated. Other degrees of freedom can be optimised, but all those being 

Crystal structure prediction requires algorithms which can search the potential energy surface of the crystal for all local minima. The search must explore the 

An analysis of the Cambridge Struetural Database (CSD) for the space group frequency distribution of crystals is shown in Table 4.1. The 13 most 

Space Group % Occurrence Crystal System Z Degrees of Freedom Cell Trans. Rot. Total 

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