Crystal structure solution of proteins by direct methods: an automatic procedure for SIR-MIR and SIRAS-MIRAS cases

In the previous paper [Giacovazzo & Siliqi (2002). Acta Cryst. A58, 590-597], a probabilistic approach for the SIR-MIR and the SIRAS-MIRAS cases has been described. The mathematical technique is able to take into account the errors arising from measurements, lack of isomorphism and heavy-atom model substructure. An automatic procedure is here described in which the conclusive formulas of that probabilistic approach have been implemented. The procedure has been successfully applied to several test structures: it can automatically provide, starting from the experimental data, high-quality electron-density maps.