Published: May 06, 2011 Copyright r 2011 American Chemical Society and Division of Chemical Education, Inc. 886 dx.doi.org/10.1021/ed1011019 | J. Chem. Educ. 2011, 88, 886–890 ARTICLE pubs.acs.org/jchemeduc Teaching Three-Dimensional Structural Chemistry Using Crystal Structure Databases. 3. The Cambridge Structural Database System: Information Content and Access Software in Educational Applications Gary M. Battle,* ,† Frank H. Allen, † and Gregory M. Ferrence ‡ † Cambridge Crystallographic Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, United Kingdom ‡ Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States P arts 1 and 2 of this series 1,2 described the important educa- tional value of experimental three-dimensional (3D) chemi- cal structures determined by X-ray crystallography and retrieved from the crystallographic databases. In part 1, we described the information content of the Cambridge Structural Database (CSD) 3a of small organic and metal organic structures and discussed a representative teaching subset of ca. 500 CSD structures that have been selected for their educational relevance. This subset is freely available via the CCDC Web site 3b together with software tools for access, visualization, and manipulation of the structures. Exploration of the CSD teaching subset using the Web applica- tion WebCSD 4 was also highlighted. In part 2, 2 we exemplified the value of the CSD teaching subset and WebCSD by describing four worked examples of their use in a teaching context. However, the complete CSD System, that is, the full database of over 500,000 structures, together with WebCSD and other advanced software for database searching, structure visualization and manipulation, and data analysis, significantly extends the range of discovery-based learning opportunities, including, for example, studies of mean molecular dimensions, stereochemistry and conformations, metal coordination sphere geometries, hy- drogen bonding and other supramolecular phenomena, and reaction pathways. In part 3 of the series, we describe the complete CSD System and its associated software and indicate its special availability to educational institutions. The accompanying article, part 4 5 illustrates a number of teaching examples that take advantage of the massive structural information content of the CSD System to broaden and enhance the chemical education experience. ’ THE CAMBRIDGE STRUCTURAL DATABASE SYSTEM The principal information content and features of a CSD structural entry were described and illustrated in part 1. 1 They can be summarized as • Organic and metal organic structures determined by single- crystal and powder X-ray diffraction and neutron diffraction. • Structures up to ca. 1,000 atoms including H atoms. • Primary results of diffraction analysis: 3D atomic coordi- nates, unit cell, etc. • 2D chemical diagram: encoded for structure and substruc- ture searching. • Bibliographic information: author(s), journal, page number(s). • Other text and numerical information: compound name(s), molecular formulas, precision indicators, physical properties (where reported). • Each structure identified by a reference code: six letters identify the compound and two digits identify different determinations of the compound. ABSTRACT: Parts 1 and 2 of this series described the educational value of experimental three-dimensional (3D) chemical structures determined by X-ray crystallography and retrieved from the crystallographic databases. In part 1, we described the information content of the Cambridge Structural Database (CSD) and discussed a representative teaching subset of ca. 500 CSD structures that have been selected for their educational relevance. In part 2, we exemplified the value of the CSD teaching subset by describing four worked examples of their use in a teaching context. Although the CSD teaching subset and its associated learning modules provide a major resource for chemical educators, there are many cases where the full CSD System, now covering more than 500,000 crystal structures, is essential to make an educational point. This is particularly true when introducing students to variance in real experimental observations, for example, where many hundreds of observations are required to generate statistically meaningful trends from the structural data or simply to introducing students to the search and manipulation of data that are commonly available in large chemical and biochemical databases. Here, we describe the complete CSD System and its associated software and highlight the extended range of discovery-based learning opportunities this affords. KEYWORDS: First-Year Undergraduate/General, Graduate Education/Research, Second-Year Undergraduate, Upper-Division Undergraduate, Chemoinformatics, Computer-Based Learning, Inquiry-Based/Discovery Learning, Internet/Web-Based Learning, X-ray Crystallography