Cambridge Structural Database
The Cambridge Structural Database (CSD), is a repository for small molecule crystal structures. Scientists use single-crystal x-ray crystallography to determine the crystal structure of a compound. Once the structure is solved, information about the structure is saved in a file (CIF format) and deposited in the CSD. Other scientists can search and retrieve structures from the database.
The information consists of the space group symmetry of the crystalline phase, its cell parameters, the relative atomic coordinates of all the atoms in the cell in 3D.
Scientists can use the CSD to compare existing data with that obtained from crystals grown in their laboratories. The information can also be used to visualize the structure in a variety of software such as atoms, powdercell etc.
It is also possible to calculate what the theoretical powder diffraction pattern of the phase would look like. This option is particularly important for analytical reasons because it facilitates the identification of phases present in a crystalline powder mixture without the need for growing crystals.
Many of the small molecules are organic compounds of the sort that could potentially act as medical drugs, and a very important use of the CSD is for structural comparisons among related molecules that can suggest new leads for drug design.
The CSD is compiled and maintained by the Cambridge Crystallographic Data Centre.