title: SAD or MAD phasing: location of the anomalous scatterers.
abstract: The method of joint probability distribution functions is applied in order to estimate the structure-factor moduli of the anomalous scatterer substructure both in the SAD (single-wavelength anomalous dispersion) and in the MAD (multi-wavelength anomalous dispersion) cases. The experimental data |F(1)(+)|, |F(1)(-)|, ..., |F(n)(+)|, |F(n)(-)| measured at n wavelengths are used simultaneously to estimate the value of |F(oa)| arising from the normal scattering of the anomalous scatterers. A practical procedure is described that, when applied to the experimental diffraction data of several proteins, shows robustness and efficiency.
authors.affiliation: Dipartimento di Scienza della Terra, Piazza Università, Perugia, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Burla
authors.forename: Benedetta
authors.initials: B
authors.lastname: Carrozzini
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Cascarano
authors.forename: Carmelo
authors.initials: C
authors.lastname: Giacovazzo
authors.forename: Giampiero
authors.initials: G
authors.lastname: Polidori
mesh_terms: D000465:Algorithms; D018360:Crystallography, X-Ray; D004798:Enzymes / Q000737:chemistry; D015233:Models, Statistical; D011338:Probability Theory; D012542:Scattering, Radiation
chemical_list: D004798:Enzymes