electronic reprint Acta Crystallographica Section A Foundations of Crystallography ISSN 0108-7673 Editor: W. Steurer On the use of the C map in Patterson deconvolution procedures Rocco Caliandro, Benedetta Carrozzini, Giovanni Luca Cascarano, Giuliana Comunale and Carmelo Giacovazzo Acta Cryst. (2013). A69, 98–107 Copyright c  International Union of Crystallography Author(s) of this paper may load this reprint on their own web site or institutional repository provided that this cover page is retained. Republication of this article or its storage in electronic databases other than as specified above is not permitted without prior permission in writing from the IUCr. For further information see http://journals.iucr.org/services/authorrights.html Acta Crystallographica Section A: Foundations of Crystallography covers theoretical and fundamental aspects of the structure of matter. The journal is the prime forum for research in diffraction physics and the theory of crystallographic structure determination by diffrac- tion methods using X-rays, neutrons and electrons. The structures include periodic and aperiodic crystals, and non-periodic disordered materials, and the corresponding Bragg, satellite and diffuse scattering, thermal motion and symmetry aspects. Spatial resolutions range from the subatomic domain in charge-density studies to nanodimensional imper- fections such as dislocations and twin walls. The chemistry encompasses metals, alloys, and inorganic, organic and biological materials. Structure prediction and properties such as the theory of phase transformations are also covered. Crystallography Journals Online is available from journals.iucr.org Acta Cryst. (2013). A69, 98–107 Rocco Caliandro et al. · Patterson deconvolution