Structural Science, Crystal Engineering and Materials

 

Acta Cryst. (2013). B69, 91-104  [ doi:10.1107/S2052519213002285 ]

The generalized invariom database (GID)

B. Dittrich, C. B. Hübschle, K. Pröpper, F. Dietrich, T. Stolper and J. J. Holstein

Synopsis: The use of aspherical atomic scattering factors in the structure refinements of organic molecular crystals is reviewed. Aspherical atomic scattering factors within the invariom database are presented as an alternative to standard atomic scattering factors in structure refinements.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 105-109  [ doi:10.1107/S2052519213003308 ]

Polarization dependence of molecular adsorption on ferroelectrics

L. Y. Kraya and R. Kraya

Synopsis: The reaction of carbon dioxide on a BaTiO₃ (001) reconstructed surface is analyzed with atomic resolution scanning tunneling microscopy.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 110-121  [ doi:10.1107/S2052519213001401 ]

Crystal structure and microstructure of synthetic hexagonal magnesium-cobalt cordierite solid solutions (Mg_2-2xCo_2xAl₄Si₅O₁₈)

F. J. Serrano, N. Montoya, J. L. Pizarro, M. M. Reventós, M. A. Kojdecki, J. M. Amigó and J. Alarcón

Synopsis: Magnesium-cobalt cordierites of hexagonal structure were synthesized by annealing glasses obtained from colloidal gel precursors and were investigated by means of X-ray powder diffraction and scanning electron microscopy. The formation of solid solutions with hexagonal structure (-cordierite) in two concurrent crystallization paths, immediate crystallization or via phase transformation of intermediate -cordierite, was observed. The parameters of the crystalline structure and microstructure were extracted from X-ray diffraction patterns as mutually correlated in dependence on cobalt content.

Online 26 February 2013

 

Acta Cryst. (2013). B69, 122-136  [ doi:10.1107/S2052519213002820 ]

Monophosphate tungsten bronzes with pentagonal tunnels: reinvestigation through the peephole of the superspace

O. Pérez, L. Elcoro, J. M. Pérez-Mato and V. Petrícek

Synopsis: The superspace formalism has been successfully applied to obtain a (3 + 1)-dimensional model unifying the description of the monophosphate tungsten bronzes with pentagonal tunnel homologous series.

Online 27 February 2013

 

Acta Cryst. (2013). B69, 137-144  [ doi:10.1107/S2052519213003126 ]

Anisotropic thermal expansion of La_n(Ti,Fe)_nO_{3n + 2} (n = 5 and 6)

A. Wölfel, P. Dorscht, F. Lichtenberg and S. van Smaalen

Synopsis: Temperature-dependent crystal structures reveal a variation of tilts of the octahedral (Ti,Fe)O₆ groups as the mechanism for the anisotropy of the thermal expansions of the title compounds. The local charge compensation is proposed as the driving force for the observed Ti/Fe chemical order.

B-IncStrDB reference: 6872EpvgNl

Online 26 February 2013

 

Acta Cryst. (2013). B69, 145-149  [ doi:10.1107/S2052519213004272 ]

Revised values of the bond-valence parameters for Te^IV-O, Te^VI-O and Te^IV-Cl

S. J. Mills and A. G. Christy

Synopsis: New bond-valence parameters r₀ and b have been re-determined for Te^IV-O, Te^VI-O and Te^IV-Cl.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 150-162  [ doi:10.1107/S205251921300376X ]

The importance of proper crystal-chemical and geometrical reasoning demonstrated using layered single and double hydroxides

I. G. Richardson

Synopsis: The importance and utility of proper crystal-chemical and geometrical reasoning in structural studies is demonstrated through the consideration of layered single and double hydroxides. New yet fundamental information is provided and it is evident that the crystal chemistry of the double hydroxide phases is much more straightforward than is apparent from the literature.

Online 26 February 2013

 

Acta Cryst. (2013). B69, 163-175  [ doi:10.1107/S2052519213001048 ]

Isoelectronic and isolobal O, CH₂, CH₃⁺ and BH₃ as electron pairs; similarities between molecular and solid-state chemistry

Á. Vegas, R. Notario, E. Chamorro, P. Pérez and J. F. Liebman

Synopsis: This work proposes the concept of a single chemistry which unifies the apparently contradictory bonding descriptions and structural models which are applied to molecular and extended solids, and thereby provides a more rational understanding of these materials.

Online 26 February 2013

 

Acta Cryst. (2013). B69, 176-183  [ doi:10.1107/S2052519213002959 ]

Investigation of non-corrin cobalt(II)-containing sites in protein structures of the Protein Data Bank

L. A. Abriata

Synopsis: A data-mining study of non-corrin cobalt(II) sites in proteins has allowed the computation of new target distances which are compared with EXAFS and CSD data; the apparent dependence of metal-donor lengths on structure resolution, previously also reported for other metals, is explored.

Online 26 February 2013

 

Acta Cryst. (2013). B69, 184-194  [ doi:10.1107/S2052519213002650 ]

Analysis of N-HO hydrogen bonds in new C(O)-NH-P(O)-based phosphoric triamides and analogous structures deposited in the Cambridge Structural Database

M. Pourayoubi, M. Toghraee, V. Divjakovic, A. van der Lee, T. Mancilla Percino, M. A. Leyva Ramírez and A. Saneei

Synopsis: Four new structures belonging to the phosphoric triamide family have been studied, and their N-HO hydrogen bonding is compared with that in 118 analogous structures from the Cambridge Structural Database.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 195-202  [ doi:10.1107/S2052519213004843 ]

Structure determination of the crystalline phase of n-butanol by powder X-ray diffraction and study of intermolecular associations by Raman spectroscopy

P. Derollez, A. Hédoux, Y. Guinet, F. Danède and L. Paccou

Synopsis: The crystal structure of n-butanol at 110 K was solved from X-ray powder diffraction. The microstructural analysis performed in the crystal was related to the description of the microstructure in the glacial state.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 203-213  [ doi:10.1107/S2052519213004879 ]

Electron densities by the maximum entropy method (MEM) for various types of prior densities: a case study on three amino acids and a tripeptide

S. J. Prathapa, S. Mondal and S. van Smaalen

Synopsis: Dynamic model densities of the invariom model and the independent atom model from high-order refinement are shown to produce reliable MEM density maps when employed as a prior density map. The performance of these priors is considerably better than of the independent atom model as prior.

Online 14 March 2013

 

Acta Cryst. (2013). B69, 214-227  [ doi:10.1107/S2052519213001772 ]

A highly hydrated -cyclodextrin/1-undecanol inclusion complex: crystal structure and hydrogen-bond network from high-resolution neutron diffraction at 20 K

D. Gallois-Montbrun, G. Le Bas, S. A. Mason, T. Prangé and S. Lesieur

Synopsis: The highly hydrated -cyclodextrin/1-undecanol host-guest complex was studied by single-crystal neutron diffraction. The supramolecular multichannel assembly based on cyclodextrin dimers which act as building blocks, each fully enclosing the lipid guest, is stabilized by an exceptionally rich water-mediated hydrogen-bond network.

Online 26 February 2013