The Structure Center server run by the International ChemoInformatics Center - Aiding Drug Design (INCIC/ADD) is a public web service located in Germany and supported by contributors world-wide. Its history dates back to the "Frederick/Bethesda Data and Online Services," and before that the "Erlangen/Bethesda Data and Online Services," which began in 1997 as a collaboration between the National Cancer Institute’s (NCI) Laboratory of Medicinal Chemistry in Bethesda, MD, USA, and researchers at the Computer Chemistry Center (CCC) at the University of Erlangen-Nuremberg, Germany, most notably Wolf-Dietrich Ihlenfeldt with his chemoinformatics toolkit CACTVS.

In its current form it is derived from the NCI’s Computer-Aided Drug Design (CADD) Group’s Chemoinformatics Tools and User Services available at

The purpose of this service is to provide structures, data, tools, programs and other useful information to the public. In addition to current and former members of the CADD Group, many others, both individuals and companies or their representatives, have contributed to these services. They are gratefully acknowledged in the individual services, such as in the credits page of the Enhanced NCI Database Browser Release 2.

No access restrictions are placed, and the general public is invited to use this site; however, the information is NOT GEARED toward the general public, and will probably be most useful for researchers working with, or interested in, chemical information, in particular for research groups engaged in computer-aided drug design.

All those data on this site that originated at the NCI are by definition in the public domain. So are many other data coming from other U.S. Government agencies. However, other data on this server, if they come from commercial entities, may have rights retained or certain usage restrictions imposed by their original suppliers. Also, links to other websites that we provide as a service to the user may lead to pages with usage restrictions for those sites as well as for the results obtained from them.