W0008

Developing Modern Crystallographic Libraries and Applications: PHENIX and the Computational Crystallography Toolbox. Ralf Grosse-Kunstleve, Nigel Moriarty, Nicholas Sauter, and Paul Adams, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, BLDG 4R0230, Berkeley, CA 94720.

Automated structure determination will be a powerful tool in the field of macromolecular crystallography and essential to the success of worldwide structural genomics efforts. Therefore, in collaboration with three international research groups we are developing a software package called PHENIX (Python-based Hierarchical ENvironment for Integrated Xtallography). This new software will provide the necessary algorithms to proceed from reduced intensity data to a refined molecular model, and facilitate structure solution for both the novice and expert crystallographer. The underlying philosophy and current status of the PHENIX package will be presented.

One of the primary goals of the PHENIX project is to create an environment that allows a tight integration between reusable software components written both in a compiled language (C++) and a flexible scripting language (Python). We make extensive use of the Computational Crystallography Toolbox (cctbx), a comprehensive and highly reusable library of core level crystallographic data objects and algorithms. The cctbx has been designed for integration into large, modular, layered software systems and is freely available under an Open Source license to foster widespread collaborations. The design of the cctbx and the tools currently available will be described. Their application in the context of PHENIX and potential use in other projects will also be discussed.