MAD and MIR

Abstract

The first part of this chapter discusses multiwavelength anomalous diffraction (MAD). In the second part of the chapter, the Solve software is described. Solve is designed to automate the solution of macromolecular X-ray structures in straightforward cases. The overall approach is to link together, in a seamless procedure, all the analysis steps that a crystallographer would normally carry out. In the process, the software converts each decision-making step into an optimization problem. A key element of the procedure is the scoring and ranking of possible solutions. For MAD data, a second key element is the conversion of MAD data to pseudo-SIRAS data, allowing for much faster structure solution. The automated procedure has been used to determine structures with as many as 56 selenium atoms in the asymmetric unit. This chapter is also available as HTML from the International Tables Online site hosted by the IUCr.