True Satellite Reflections in the Refinement of Displacively Modulated, Composite Crystal Structures.

摘要

In a composite crystal structure, consisting of two (or more) sublattices, incommensurate f. inst. along c, main reflections of one sublattice (say (hklO)) are also /th order satellite reflections of the other sublattice with main reflections (hkOm).* Therefore, the inclusion of true satellite reflections in the least-squares refinement of displacively modulated, composite structures, are usually not considered necessary for description of the displacive modulation. True satellite reflections are those satellite reflections, that are not main reflections of any of the sublattices, i.e. with (hklm), I & 0 and m * 0. We have measured true satellite reflections from two composite crystals and analyzed their influence on the structural model.