view article

Figure 1
Part of the Argand diagram showing various contributions to the scattering factors. The measured amplitudes of both Friedel mates and their mean (Ft+, Ft- and Ft) are shown in black and green, those of the anomalous scatterers (Fa and [F''_{a}]) in red and the resultant contribution of the normally scattering atoms (Fp) in blue. (The likely contribution of Fa has been grossly exaggerated to clarify the figure.) The magnitudes of Ft+ and Ft- are known and once the anomalous substructure has been positioned, the red vectors can be calculated. Two solutions for Ft are then possible, with their phase, φT, symmetrically placed on either side of φA − 90°. The contribution of the normal scatterers, Fp will be different in the two cases.

Journal logoBIOLOGICAL
ISSN: 1399-0047
Follow Acta Cryst. D
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds