This Cambridge Structural Database (CSD) project is located at the Cambridge Crystallographic Data Centre in England. This award from the Division of Chemistry, Office of Special Projects will provide approximately 25 percent of the support for access to this database by U.S. scientists from the academic, government, and not-for-profit research communities. This contribution will be transferred to the National Institutes of Health (NIH) as the Foundation becomes a co-supporter of the CSD. The U.S. has over 1600 crystallographers who are potential users of this database. The CSD contains the most comprehensive collection of evaluated crystallographic data in the world. Data for about 80,000 organic and organometallic crystal structures were included in the CSD as of January, 1991. Atomic coordinates, chemical connectivity tables, bibliographic data fields including reference sources for the data, and coordinates for chemical structure diagrams for each molecule are part of the system. Software for search, retrieval, and analysis of the data will be supplied as well as any improvements and updates of the software. About 8000 new crystal structures will be added to the data base yearly. Thus this international resource will remain accessible to crystallographic community and other users in the U.S. through the joint support of NSF and NIH.