Acta Crystallographica Section B

Structural Science

Volume 68, Part 1 (February 2012)

Cover illustration: A high-angle annular darkfield scanning transmission electron microscopy image of the decagonal quasicrystal Al₇₂Co₈N_i20 overlaid with a structure model. Clusters of type 1 (occupied center) highlight transition metal sites (white spheres) and clusters of type 2 (empty center) possess both transition metal and mixed aluminum/transition metal (red) sites. Decagonal-shaped clusters are outlined and exhibit two types of overlap as a unifying building feature of aperiodic quasicrystals of decagonal Al-Co-Ni, Al-Co-Cu and Al-Fe-Ni [Deloudi et al. (2011). Acta Cryst. B67, 1-17, based on Abe & Tsai (2004) J. Non-Cryst. Solids, 334, 198-201]. The 2011 Nobel prize in chemistry was awarded to D. Shechtman for his discovery of quasicrystals.

research papers
short communications
addenda and errata
international union of crystallography
book reviews

research papers

Acta Cryst. (2012). B68, 1-7 [ doi:10.1107/S0108768111046751 ]

Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, -Sb₂O₃, from high-resolution synchrotron powder diffraction data

D. Orosel, R. E. Dinnebier, V. A. Blatov and M. Jansen

Synopsis: The crystal structure of a new quenchable high-pressure-high-temperature modification of antimony(III) oxide, [gamma] -Sb₂O₃, with rare 3,3T8 topology has been determined from high-resolution synchrotron powder diffraction data.

Online 18 January 2012

Acta Cryst. (2012). B68, 8-14 [ doi:10.1107/S0108768111046738 ]

High-precision absolute lattice parameter determination of SrTiO₃, DyScO₃ and NdGaO₃ single crystals

M. Schmidbauer, A. Kwasniewski and J. Schwarzkopf

Synopsis: The lattice parameters of SrTiO₃ and DyScO₃, and NdGaO₃ single crystals have been measured with high precision at room temperature with a relative accuracy of the order of 10^-5.

Online 6 January 2012

Acta Cryst. (2012). B68, 15-23 [ doi:10.1107/S010876811104688X ]

Structure of the new mineral sarrabusite, Pb₅CuCl₄(SeO₃)₄, solved by manual electron-diffraction tomography

M. Gemmi, I. Campostrini, F. Demartin, T. E. Gorelik and C. M. Gramaccioli

Synopsis: The crystal structure of the new mineral sarrabusite Pb₅CuCl₄(SeO₃)₄ has been solved using a manual and an automated version of the new electron-diffraction tomography technique combined with the precession of the electron beam.

Online 6 January 2012

Acta Cryst. (2012). B68, 24-33 [ doi:10.1107/S0108768111054061 ]

Structure maps for A^I₄A^II₆(BO₄)₆X₂ apatite compounds via data mining

P. V. Balachandran and K. Rajan

Synopsis: This paper describes a data-driven strategy using principal component analysis and K-means clustering to discover the best classifiers for constructing structure maps.

Online 18 January 2012

Acta Cryst. (2012). B68, 34-39 [ doi:10.1107/S0108768111053493 ]

Polymorphism of Li₂Zn₃

V. Pavlyuk, I. Chumak and H. Ehrenberg

Synopsis: Crystal structures of low- and high-temperature modifications of a binary phase Li₂Zn₃ were demonstrated by single-crystal X-ray diffraction techniques. The low-temperature modification is a disordered variant of Li₅Sn₂, space group $R\\bar 3m$ . The high-temperature modification crystallizes as an anti-type to Li₅Ga₄, space group $P\\bar 3m1$ . Two polymorphs can be described as derivative structures to binary Li₅Ga₄, Li₅Sn₂, Li₁₃Sn₅, Li₈Pb₃, CeCd₂ and CdI₂ phases.

Online 18 January 2012

Acta Cryst. (2012). B68, 40-56 [ doi:10.1107/S0108768111053298 ]

Structural phase transition to disorder low-temperature phase in [Fe(ptz)₆](BF₄)₂ spin-crossover compounds

J. Kusz, M. Zubko, R. B. Neder and P. Gütlich

Synopsis: In the spin-crossover compound [Fe(ptz)₆](BF₄)₂ six different phases are observed. The low-spin disordered phase was solved in a novel approach to accommodate the very unusual twinning.

Online 18 January 2012

Acta Cryst. (2012). B68, 57-65 [ doi:10.1107/S0108768111051159 ]

Face-to-face stacking of quinoid rings of alkali salts of bromanilic acid

K. Molcanov and B. Kojic-Prodic

Synopsis: A series of alkali bromanilate salts has been studied. The quinoid rings of hydrogen bromanilate anions stack face-to-face with a short centroid separation of 3.3 Å and no offset.

Online 6 January 2012

Acta Cryst. (2012). B68, 66-70 [ doi:10.1107/S0108768111046593 ]

An order-disorder phase transition in the structure of C₆₀·4benzene

M. M. Olmstead, A. L. Balch and H. M. Lee

Synopsis: The crystal structure of C₆₀·4benzene has been re-examined at 157, 93 and 13 K, and found to undergo an order-disorder phase transition that enables more accurate structural information for the most common fullerene to be obtained at low temperature.

Online 6 January 2012

Acta Cryst. (2012). B68, 71-79 [ doi:10.1107/S0108768111052608 ]

Hydrogen-bridged chelate ring-assisted -stacking interactions

H. Karabiyik, H. Karabiyik and N. Ocak Iskeleli

Synopsis: Novel hydrogen-bridged ring-assisted [pi] -stacking interactions are presented and discussed.

Online 6 January 2012

Acta Cryst. (2012). B68, 80-88 [ doi:10.1107/S0108768111046295 ]

Study of the single-crystal X-ray diffuse scattering in paracetamol polymorphs

E. J. Chan and D. J. Goossens

Synopsis: Diffuse X-ray scattering experiments were performed on single crystals of the two most commonly found polymorphs of paracetamol. Diffraction data calculated from simple Monte Carlo models of these forms are in good agreement with the observed data. Investigation of the models show that disordered displacements similar to that in the real crystal can be generated in a model based solely on knowledge of intermolecular potentials and atomic coordinates obtained from a Bragg diffraction experiment. Comparison of the correlated motions between the crystal forms revealed no further insight into the form (II) [rightwards arrow] (I) transition.

Online 18 January 2012

short communications

Acta Cryst. (2012). B68, 89-90 [ doi:10.1107/S0108768111054371 ]

Revision of the Mg(ClO₄)₂·4H₂O crystal structure

L. A. Solovyov

Synopsis: The restrained Rietveld analysis of the crystal structure of magnesium perchlorate tetrahydrate, Mg(ClO₄)₂(H₂O)₄ [Robertson & Bish (2010). Acta Cryst. B66, 579-584], is revised. The structure is re-refined in the C2/m space group by the derivative difference method, anisotropically for all non-H atoms and isotropically for H atoms without restraints.

Online 18 January 2012

addenda and errata

Acta Cryst. (2012). B68, 91 [ doi:10.1107/S0108768111046908 ]

Lattice constants and thermal expansion of H₂O and D₂O Ice Ih between 10 and 265 K. Addendum

K. Röttger, A. Endriss, J. Ihringer, S. Doyle and W. F. Kuhs

Synopsis: An addendum to the article by Röttger et al. [Acta Cryst. (1994). B50, 644-648].

Online 6 January 2012

Acta Cryst. (2012). B68, 92 [ doi:10.1107/S0108768111051639 ]

Water channel structure of bassanite at high air humidity: crystal structure of CaSO₄·0.625H₂O. Corrigendum

H. Schmidt, I. Paschke, D. Freyer and W. Voigt

Synopsis: Corrigendum to the article by Schmidt et al. [Acta Cryst. (2011). B67, 467-475].

Online 6 January 2012

international union of crystallography

Acta Cryst. (2012). B68, 93-97 [ doi:10.1107/S0108768111050099 ]

Notes for authors 2012

Online 18 January 2012

book reviews

Acta Cryst. (2012). B68, 98-99 [ doi:10.1107/S010876811105484X ]

Structural Mineralogy and Inorganic Crystal Chemistry

Online 18 January 2012

Acta Crystallographica Section B

Structural Science

Volume 68, Part 1 (February 2012)

research papers

Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, -Sb2O3, from high-resolution synchrotron powder diffraction data

D. Orosel, R. E. Dinnebier, V. A. Blatov and M. Jansen

High-precision absolute lattice parameter determination of SrTiO3, DyScO3 and NdGaO3 single crystals

M. Schmidbauer, A. Kwasniewski and J. Schwarzkopf

Structure of the new mineral sarrabusite, Pb5CuCl4(SeO3)4, solved by manual electron-diffraction tomography

M. Gemmi, I. Campostrini, F. Demartin, T. E. Gorelik and C. M. Gramaccioli

Structure maps for AI4AII6(BO4)6X2 apatite compounds via data mining

P. V. Balachandran and K. Rajan

Polymorphism of Li2Zn3

V. Pavlyuk, I. Chumak and H. Ehrenberg

Structural phase transition to disorder low-temperature phase in [Fe(ptz)6](BF4)2 spin-crossover compounds

J. Kusz, M. Zubko, R. B. Neder and P. Gütlich

Face-to-face stacking of quinoid rings of alkali salts of bromanilic acid

K. Molcanov and B. Kojic-Prodic

An order-disorder phase transition in the structure of C60·4benzene

M. M. Olmstead, A. L. Balch and H. M. Lee

Hydrogen-bridged chelate ring-assisted -stacking interactions

H. Karabiyik, H. Karabiyik and N. Ocak Iskeleli

Study of the single-crystal X-ray diffuse scattering in paracetamol polymorphs

E. J. Chan and D. J. Goossens

short communications

Revision of the Mg(ClO4)2·4H2O crystal structure

L. A. Solovyov

addenda and errata

Lattice constants and thermal expansion of H2O and D2O Ice Ih between 10 and 265 K. Addendum

K. Röttger, A. Endriss, J. Ihringer, S. Doyle and W. F. Kuhs

Water channel structure of bassanite at high air humidity: crystal structure of CaSO4·0.625H2O. Corrigendum

H. Schmidt, I. Paschke, D. Freyer and W. Voigt

international union of crystallography

Notes for authors 2012

book reviews

Structural Mineralogy and Inorganic Crystal Chemistry

Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, -Sb₂O₃, from high-resolution synchrotron powder diffraction data

High-precision absolute lattice parameter determination of SrTiO₃, DyScO₃ and NdGaO₃ single crystals

Structure of the new mineral sarrabusite, Pb₅CuCl₄(SeO₃)₄, solved by manual electron-diffraction tomography

Structure maps for A^I₄A^II₆(BO₄)₆X₂ apatite compounds via data mining

Polymorphism of Li₂Zn₃

Structural phase transition to disorder low-temperature phase in [Fe(ptz)₆](BF₄)₂ spin-crossover compounds

An order-disorder phase transition in the structure of C₆₀·4benzene

Revision of the Mg(ClO₄)₂·4H₂O crystal structure

Lattice constants and thermal expansion of H₂O and D₂O Ice Ih between 10 and 265 K. Addendum

Water channel structure of bassanite at high air humidity: crystal structure of CaSO₄·0.625H₂O. Corrigendum