Download citation
Download citation
link to html
This paper presents several general properties of systematic absences that are available before unit-cell parameters and the space group have been determined. The properties are given in the form of distribution rules of Miller indices corresponding to systematic absences on a topograph. A topograph is a graph whose edges are associated with a set of four lattice vectors satisfying Ito's equation 2(|l1*|2 + |l2*|2) = |l1* + l2*|2 + |l1* - l2*|2. It is possible to integrate global information about extinct reflections by using topographs. As an example of the application of these rules, a new powder auto-indexing algorithm is introduced, focusing on its theoretical aspects.

Supporting information

pdf

Portable Document Format (PDF) file https://doi.org/10.1107/S0108767313021740/sc5063sup1.pdf
Appendices A, B, C and D


Follow Acta Cryst. A
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds