Abstract

<h2>Acta Crystallographica</h2><h3></h3><h3>0365-110X</h3> <h2>research papers</h2> Volume 23 Part 6 Pages 898-901 December 1967 <h2>A new method of obtaining phase angles of structure factors of non-centrosymmetric structure by the use of anomalous dispersion</h2> D. Unangst, E. Müller, J. Müller and B. Keinert Acta Cryst. (1967). 23, 898 A New Method for Obtaining Phase Angles of Structure Factors of Non-Centrosymmetrie Structures by the Use of Anomalous Dispersion BY DIETRICH UNANGST, EBERHARD MOLLER, JORGEN MOLLER AND BERND KEINERT Physikalisches Institut der Friedrich-Schiller-Universit~it, 69 Jena, Max-Wien-Platz 1, Germany (DDR) (Received 23 February 1967) A method is described for finding the phases of structure factors by using the ratio IFI~/IPl~ instead of the Bijvoet difference Ifl~- IFP. The'influence of errors of measurement is pointed out and a com- parison with the method of Bijvoet differences is made. Introduction and theory It is possible to obtain the phases of structure factors by making use of the effects of anomalous dispersion. The method is based on experimental measurements of the Bijvoet differences IFI2-IFIz between pairs of inverse reflexions hkl and hkl produced by the imaginary component Aft' of the scattering factor (Ramachan- dran, 1964). In order to avoid difficulties and errors of measurement in the determination