Incommensurate modulations made visible by the Maximum Entropy Method in superspace
-
Lukás Palatinus
Abstract
This paper presents the application of the Maximum Entropy Method (MEM) to structure solution of incommensurately modulated structures within the superspace formalism. The basic principles of the MEM are outlined, and its generalization toward superspace is discussed. Possible problems in MEM reconstructions and their solutions are summarized. They include series-termination errors in the reconstructed electron density, the effect of insufficient constraints, and the effect of missing data. The use of the MEM in superspace is illustrated by three examples: the structure of the misfit-layer compound (LaS)1.14NbS2, the structure of the high-pressure phase III of bismuth, and the modulated structure of ammonium tetrafluoroberyllate. It is shown that the MEM is able to extract more information about the modulation functions than can be obtained by structure refinements. The MEM can also be used for the study of accurate charge densities of modulated structures. An illustration is given by the charge density of ammonium tetrafluoroberyllate.
© 2004 Oldenbourg Wissenschaftsverlag GmbH
Articles in the same Issue
- Self-reciprocal redundant vector stars
- Editorial: Incommensurate Crystallography of Modulated and Composite Crystals
- An elementary introduction to superspace crystallography
- Methods of structural analysis and computer program JANA2000
- Flexible phases, modulated structures and the transmission electron microscope
- X-ray diffuse scattering as precursor of incommensurate Peierls transitions in one-dimensional organic charge transfer conductors
- Incommensurate modulations made visible by the Maximum Entropy Method in superspace
- The study of incommensurate structures as a probe to reveal atomic interactions in crystals
- High temperature structures of LiKSO4 crystals: normal and incommensurate phases
- Incommensurate crystal structures in the elements at high pressure
- Structural phase transitions in iodine under high pressure
- Incommensurate crystal structure of LiCd4(VO4)3
- An electron and X-ray diffraction study of the compositely modulated barium nickel hollandite Bax(NixTi8—x)O16, 1.16 < x < 1.32, solid solution
- Book Reviews
- Books Received
Articles in the same Issue
- Self-reciprocal redundant vector stars
- Editorial: Incommensurate Crystallography of Modulated and Composite Crystals
- An elementary introduction to superspace crystallography
- Methods of structural analysis and computer program JANA2000
- Flexible phases, modulated structures and the transmission electron microscope
- X-ray diffuse scattering as precursor of incommensurate Peierls transitions in one-dimensional organic charge transfer conductors
- Incommensurate modulations made visible by the Maximum Entropy Method in superspace
- The study of incommensurate structures as a probe to reveal atomic interactions in crystals
- High temperature structures of LiKSO4 crystals: normal and incommensurate phases
- Incommensurate crystal structures in the elements at high pressure
- Structural phase transitions in iodine under high pressure
- Incommensurate crystal structure of LiCd4(VO4)3
- An electron and X-ray diffraction study of the compositely modulated barium nickel hollandite Bax(NixTi8—x)O16, 1.16 < x < 1.32, solid solution
- Book Reviews
- Books Received
