Crystallography Open Database - an open-access collection of crystal structures

Abstract

The Crystallography Open Database (COD), which is a project that aims to gather all available inorganic, metal-organic and small organic molecule structural data in one database, is described. The database adopts an open-access model. The COD currently contains ∼80 000 entries in crystallographic information file format, with nearly full coverage of the International Union of Crystallography publications, and is growing in size and quality.

Figure 1

The COD deposition procedure. In this data flow diagram, circles indicate automatic processes and arrows show the data paths. As in control flow diagrams, a trapezoid indicates manual processes and a rhomb indicates a process where a decision to divert data via different paths is taken. Names after the colons in each node are the names of the Unix tools or COD-specific programs that were used for that operation. Rectangles are abstract (web) data sources – data sources depicted in pink provide crystallographic and chemical information (coordinates, symmetry data, formulae), while those depicted on a blue background provide bibliographic data. Cylinders denote internal COD disk storage facilities (databases). File extensions indicate file formats used. The .mrk file format is an intermediate format similar to XML designed for ease of parsing and editing, and used only internally by the COD deposition scripts.