MacCHESS: supporting a World-class Facility for Crystallography at CHESS D. Szebenyi, M. Cook, U. Englich, R. Gillilan, Q. Hao, C. Heaton, I. Kriksunov, M. Love, W. Miller, D. Schuller, and D. Thiel; MacCHESS, Cornell University, Ithaca, NY 14853.

MacCHESS ("Macromolecular diffraction at CHESS") is an NIH-funded Research Resource which supports crystallographers using the Cornell High Energy Synchrotron Source, as well as carrying out research to improve the facility. A number of recent and planned improvements are enhancing the opportunities for crystallography at CHESS:

Operation - Starting in Fall 2002, CHESS operates in a dedicated mode rather than parasitically on the CESR colliding-beam facility.

Detectors - All macromolecular crystallography stations have ADSC Quantum CCD detectors. The F-1 station has a unique two-detector system giving a very large flat or V-shaped area for recording diffraction patterns.

Automation - Systems for automatically mounting and centering crystals are under development.

Data collection software - The ADX package from ADSC, and associated programs, have been customized and enhanced for use at CHESS; special modifications for special experiments are readily available.

Data processing and structure solution software - the DPS/Mosflm/CCP4 data reduction interface is supported and continues to be developed by MacCHESS, as are other programs such as SAPI and FSEARCH. Many standard packages such as HKL, XDS, CCP4, CNS, Shake-and-Bake, and SOLVE/RESOLVE are installed at CHESS, and help in their use is available.