issue contents

ISSN: 2052-5206

February 2016 issue

Highlighted illustration

Cover illustration: The structure of crocoite in the anion-centred description. The Charge Distribution (CHARDI) analysis shows that the structure can be described as centred on cation-centred homoligand polyhedra or anion-centred heteroligand polyhedra [see Nespolo (2016). Acta Cryst. B72, 51-66].

scientific commentaries

Acta Cryst. (2016). B72, 1-2
doi: 10.1107/S2052520616001062
link to html
Some comments on the review by Sim et al. [(2016). Acta Cryst. B72, 3–19] are given. The review is devoted to hexagonal multiferroics RMnO3, in which there are ferroelectric and magnetic orders. Strong interaction between these orders causes a series of interesting properties of multiferroics.

feature articles

Acta Cryst. (2016). B72, 3-19
doi: 10.1107/S2052520615022106
link to html
Here we present a review of the crystal and magnetic structure as well as the spin dynamics of two-dimensional triangular lattice multiferroic hexagonal manganite RMnO3.

research papers

Acta Cryst. (2016). B72, 20-28
doi: 10.1107/S2052520615018582
link to html
This paper presents a study of the structures and physicochemical properties of ciprofloxacin's novel salts.

Acta Cryst. (2016). B72, 29-38
doi: 10.1107/S2052520615021083
link to html
This article discusses a new method to determine the compositional fluctuations in partially stabilized zirconia based on the comparison of the X-ray diffraction patterns of partially transformed samples.

Acta Cryst. (2016). B72, 39-50
doi: 10.1107/S2052520615019538
link to html
An experimental charge density study on polymorph (III) of carbamazepine is in excellent agreement with theory and a Hirshfeld atom refinement based on the X-ray data provides positional and anisotropic displacement parameters for the H atoms closely similar to those obtained from the neutron diffraction data. X-ray and neutron diffraction data on the dihydrate of carbamazepine strongly indicate a disordered orthorhombic crystal structure in Cmca, rather than a monoclinic crystal structure in P21/c.

Acta Cryst. (2016). B72, 51-66
doi: 10.1107/S2052520615019472
link to html
A new, more general approach to treat heteroligand polyhedra in the charge distribution algorithm is presented.

Acta Cryst. (2016). B72, 67-74
doi: 10.1107/S2052520615021897
link to html
Utilizing the Burgers Orientation Relationship and the four-dimensional Frank space, we were able to identify the multiplicity of crystallographically equivalent variants generated by iterative phase transformations (h.c.p. to b.c.c. and vice versa) in pure titanium.

Acta Cryst. (2016). B72, 75-86
doi: 10.1107/S2052520615019083
link to html
The electron density of a thiophene compound was determined experimentally and theoretically, using a multipolar model and a virtual spherical atoms model.

Acta Cryst. (2016). B72, 87-95
doi: 10.1107/S2052520615019678
link to html
The preparation and structural characterization of co-crystals of cinnamic acid derivatives with pyridyl co-crystallizers are reported through recrystallization and solvent drop grinding.

link to html

Rietveld refinement of complementary synchrotron powder X-ray diffraction and neutron diffraction data leads to the resolution of the structure of the monoclinic phase of calcium pyrophosphate dihydrate (m-CPPD) including the determination of the precise position of the hydrogen atoms. These new structural data are of particular importance to further understand in vivo phenomena related to osteoarthritis: m-CPPD phase formation and evolution, and structure–inflammatory response relationships.

link to html
Single strands of copper terephthalate units are connected by a tripodal ligand that bridges two copper(II) nodal points to form a double-stranded one-dimensional chain. The isolated cavities in the assembly stabilize a pair of water trimers by hydrogen bonding. The coordination polymer also catalyses the Glaser–Hay coupling reaction.

link to html
The structure of Cs3ScSi6O15 has been solved and refined as an incommensurately modulated crystal structure in (3+1)-dimensional superspace. Large positional modulations of the constituting atoms give rise to satellite reflections up to the fourth order.

link to html
Reversible chairskew flipping of the 1,3,2-dioxaphosphorinane ring has been shown to take place during three reversible single-crystal-to-single-crystal phase transitions in the β-NH4[(MeO)2cDHAP] crystal, revealing the conformational flexibility of the O/P/O/C/C/C ring in the solid state.

link to html
The crystal structure of the multiferroic melilite Ca2CoSi2O7 is determined by means of single-crystal neutron diffraction at 10 K.

link to html
Cs3(HSO4)2(H2PO4) and Cs4(HSO4)3(H2PO4) single crystals were obtained for the first time based on a systematic study of the phase diagram of the CsHSO4–CsH2PO4–H2O ternary system and studied by X-ray diffraction. Dielectric and optical properties of these crystals were determined to establish structural conditionality for anomalies in their physical properties.

link to html
The electron density of a bioactive benzoxazolone was determined experimentally by high-resolution X-ray diffraction. Comparison with the results from theoretical calculations reveals the effects of intermolecular interactions and polarization in the crystalline solid.

link to html
A variable-temperature single-crystal X-ray diffraction study of a synthetic BaTiO3 perovskite has been performed over the temperature range 298–778 K.

short communications

link to html
A new salt of L-valinium hydrogen maleate was used as an example to study structure-forming units in amino acid maleates. Model calculations have shown the C22(12) motif (common for most maleates) to be crucial for the thermodynamic stability of the structure.

book reviews

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