Tables for
Volume F
Crystallography of biological macromolecules
Edited by E. Arnold, D. M. Himmel and M. G. Rossmann

International Tables for Crystallography (2012). Vol. F, ch. 16.1, p. 416   | 1 | 2 |


G. M. Sheldrick,a C. J. Gilmore,b H. A. Hauptman,c C. M. Weeks,c* R. Millerc and I. Usónd

aLehrstuhl für Strukturchemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany,bDepartment of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK,cHauptman–Woodward Medical Research Institute, Inc., 700 Ellicott Street, Buffalo, NY 14203–1102, USA, and dInstitució Catalana de Recerca i Estudis Avançats at IBMB-CSIC, Barcelona Science Park. Baldiri Reixach 15, 08028 Barcelona, Spain
Correspondence e-mail:


The conditional probability distribution, [P(\Phi_{\bf HK})], of the three-phase structure invariants, [\Phi_{\bf HK}], having associated parameters AHK with values of 0, 1, 2, 4 and 6. When A ≃ 0, all values of [\Phi_{\bf HK}] are equally likely, and no information useful for phase determination is available. However, the sum of the three phases for most invariants with A ≃ 6 is close to 0°, and an estimate of one phase can be made if the other two are known.