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Published on: February 15, 2015
Sheldrick's 1.2 A rule and beyond
Richard J Morris1, Gérard Bricogne
1Global Phasing Ltd, Sheraton House, Castle Park, Cambridge CB3 0AX, England.
Abstract:
An average profile of squared normalized structure factors as a function of resolution, /E/2>(d*), calculated from a large ensemble of high-resolution protein models, is presented. An interpretation is given that provides a structural explanation for Sheldrick's 1.2 A rule for the applicability of direct methods. The implications for the potential effectiveness of extended direct methods, incorporating stereochemical knowledge, are discussed.
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