Introduction to SHELXS-96

SHELXS-96 is a FORTRAN-77 program for the solution of crystal structures from X-ray or neutron diffraction data, and is primarily designed for single crystal data of small structures (1-500 unique atoms) at atomic resolution, but is also useful for the location of heavy atoms from macromolecular isomorphous or anomalous delta-F data. The use of the program with SIR, OAS or MAD FA data is described near the end of these notes. SHELXS-96 is intended to be easy to install and use on a wide variety of computers. It is designed to replace SHELXS-86, and to be used in conjunction with SHELXL-96 (crystal structure refinement).

SHELXS-96 is general and efficient for all space groups in all settings, and there are no arbitrary limits to the size of problems which can be handled, except for the total memory available to the program. All instructions are in machine independent free format, with extensive use of default settings to minimize the amount of input required from the user. Instructions and data are taken from two standard (ASCII) text files, so that input files can easily be transferred between different computers.