issue contents

ISSN: 2053-2733

January 2014 issue

Highlighted illustration

Cover illustration: Atomic pair distribution function (PDF) analysis is having a major impact on the study of atomic correlations and local structure in nanomaterials. The methodology is extended to short-range magnetic correlations through the magnetic pair distribution function (mPDF) in the article by Frandsen et al. [Acta Cryst. (2014), A70, 3-11].  This will give new insight into magnetic correlations in nanomaterials and short-range-ordered magnetism in bulk materials, such as the spin-density wave shown here with its mPDF superimposed.


scientific commentaries

Acta Cryst. (2014). A70, 1-2
doi: 10.1107/S2053273313033925
link to html
The recent application of the total scattering method to magnetic systems is discussed. The ability to determine the magnetic pair distribution function opens the door to the study of local order in magnetic systems ranging from multiferroics to dilute magnetic semiconductors.

research papers

Acta Cryst. (2014). A70, 3-11
doi: 10.1107/S2053273313033081
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An analytical expression for the magnetic pair distribution function is derived. Examples and discussion of its utility for investigating magnetic structure are provided.


research papers

Acta Cryst. (2014). A70, 12-23
doi: 10.1107/S2053273313023887
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An approach to the determination of the symmetry groups of structural analogs of single-wall carbon nanotubes using ideas in color symmetry theory is described. The line group structures of the symmetry groups of BN, BC3, BCN and BC2N nanotubes are identified. An extension of the method to address nanotubes with non-hexagonal symmetry is also presented.

Acta Cryst. (2014). A70, 24-38
doi: 10.1107/S2053273313023176
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It was found that there are 17 803 types of double antisymmetry space groups. This is four fewer than previously thought. When rotation-reversal symmetry and time-reversal symmetry are considered, this implies that there are 17 803 distinct types of symmetry that a crystal may exhibit.

Acta Cryst. (2014). A70, 39-48
doi: 10.1107/S2053273313026600
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Based on benchmark synchrotron powder X-ray diffraction data, the subtleties in the electron density of diamond are explored. A contraction of the core density inherently linked to covalent bond formation is experimentally observed.

Acta Cryst. (2014). A70, 49-63
doi: 10.1107/S2053273313027605
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Group-theoretical methods of the Landau theory of phase transitions are used to investigate the structures of ordered spinels. All types of ordered spinels are established.

Acta Cryst. (2014). A70, 64-71
doi: 10.1107/S2053273313030416
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Darwin's dynamical theory of X-ray diffraction has been developed for lateral crystalline structures having rectangular cross section. This approach allows one to calculate rocking curves as well as reciprocal-space maps.

Acta Cryst. (2014). A70, 72-91
doi: 10.1107/S2053273313028313
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A comprehensive analysis of various properties derived from multiple high-resolution X-ray diffraction experiments is reported. The study indicates the precision and reliability of the analysed quantities and their usefulness in charge-density studies of organic molecules.

book reviews

Acta Cryst. (2014). A70, 92-94
doi: 10.1107/S2053273313027642
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