Patterson function and δ recycling: derivation of the phasing equations
Abstract:Two phasing equations based on the Fourier syntheses δP = T −1[(E 2−〈E 2〉)exp(iΦ)] and δM = T −1[(E−〈E〉)exp(iΦ)] were recently described [Rius (2012). Acta Cryst. A68, 77–81] (E is the quasi‐normalized structure factor and 〈E〉 is the average over all reflections). These equations were found by comparison with the direct methods origin‐free modulus sum function and constitute the core of the `δ recycling' phasing procedure. The derivation of these phasing equations from the minimization of a residual (R P) between two differently calculated density functions (one of them including the positivity constraint) is shown.
Document Type: Short Communication
Affiliations: Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, 08193-Bellaterra, Catalonia, Spain
Publication date: May 1, 2012