Acta Crystallographica Section B: Structural Science Volume 64, Part 4 (August 2008) Copyright (c) International Union of Crystallography 2008 ----------------------------------------------------------------- [Issue Author Index][Volume Author Index] * research papers * short communications * addenda and errata ----------------------------------------------------------------- research papers ----------------------------------------------------------------- Acta Cryst. (2008). B64, 405-416 [ doi:10.1107/S0108768108012317 ] Incommensurate structure of InAl[1 - x]Ti[x]O[3 + x/2] [x = 0.701 (1)]: comparison between modulated and composite models P. J. Bereciartua, F. J. Zuniga and T. Breczewski Synopsis: The monoclinic phase of the compound InAl[1 - x]Ti[x]O[3 + x/2] with x = 0.701 (1) has been studied through single-crystal X-ray diffraction. Online 10 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 417-425 [ doi:10.1107/S0108768108016029 ] Incommensurate structure of Ca[2]Al[2]O[5] at high temperatures - structure investigation and Raman spectroscopy B. Lazic, H. Krueger, V. Kahlenberg, J. Konzett and R. Kaindl Synopsis: A high-temperature X-ray diffraction study revealed that brownmillerite-type Ca[2]Al[2]O[5] transforms to an incommensurately modulated structure at elevated temperatures. The characterization is completed by Raman spectroscopy. Online 10 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 426-437 [ doi:10.1107/S0108768108018144 ] Inorganic structures in space group P3m1; coordinate analysis and systematic prediction of new ferroelectrics S. C. Abrahams Synopsis: Twelve families with the space group P3m1 are shown to satisfy the structural criteria for, and hence may be predicted to exhibit, the property of ferroelectricity. Sixteen other families are likely to be nonpolar with a similar number having reduced predictive properties. Online 17 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 438-447 [ doi:10.1107/S0108768108019022 ] Order, disorder and structural modulations in Bi-Fe-W-O-Br Sillen-Aurivillius intergrowths D. Avila-Brande, A. R. Landa-Canovas and L. C. Otero-Diaz Synopsis: A new Sillen-Aurivillius intergrowth Bi[4]Fe[1/3]W[2/3]O[8]Br has been studied by transmission electron microscopy and associated techniques, along with its structural evolution when heated at high temperature (1473 K). Online 17 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 448-455 [ doi:10.1107/S0108768108016170 ] Special features of intermolecular bonding A...D (A = Si, Ge and D = nucleophile) in crystal structures A. V. Vologzhanina, A. A. Korlyukov and M. Y. Antipin Synopsis: Crystal structure analysis of silicon- and germanium-containing compounds within the framework of the stereoatomic model was carried out to distinguish the quantitative descriptors of the intermolecular contacts Si...D and Ge...D. Online 10 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 456-465 [ doi:10.1107/S0108768108010604 ] X-ray diffuse scattering from HMTA: analysis via a Monte Carlo model D. J. Goossens, A. P. Heerdegen and T. R. Welberry Synopsis: The occupancy and displacive short-range order in HMTA, the adduct of hexamethylenetetramine and azelaic acid, have been examined using X-ray diffuse scattering, determining the ordering of molecular flips and the key intermolecular interactions. Online 14 June 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 466-475 [ doi:10.1107/S010876810801793X ] High-pressure structural study of L-[alpha]-glutamine and the use of Hirshfeld surfaces and graph-set notation to investigate the hydrogen bonding present in the structure up to 4.9 GPa P. Lozano-Casal, D. R. Allan and S. Parsons Synopsis: The following article explores the effect of high pressure on the L-[alpha]-glutamine crystal structure. Results show that the main structural feature to be influenced by pressure is the hydrogen bond network. Online 17 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 476-482 [ doi:10.1107/S0108768108012779 ] Pressure-freezing with conformational conversion of 3-aminopropan-1-ol molecules R. Gajda and A. Katrusiak Synopsis: 3-Aminopropan-1-ol molecules change their conformation from a pseudo-ring in the vapour and liquid to an extended one in the solid state, and the intramolecular hydrogen bonds are replaced with intermolecular ones. The liquid freezes at 0.1 MPa/284 K and at 0.13 GPa/296 K in the same polar monoclinic structure, space group Cc. Online 14 June 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 483-490 [ doi:10.1107/S0108768108011476 ] Conformational richness and multiple Z' in salt co-crystal of N-methylpiperidine betaine with N-methylpiperidine betaine hexafluorosilicate R. Thaimattam, M. Szafran, Z. Dega-Szafran and M. Jaskolski Synopsis: The crystal structure of a 4:1 complex between N-methylpiperidine betaine (N-carboxymethyl-N-methylpiperidinium inner salt) and hexafluorosilicic acid reveals six different dimers of hemiprotonated betaine molecules, formed via very short O...H...O hydrogen bonds between the carboxylic functions. Online 14 June 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 491-496 [ doi:10.1107/S0108768108015437 ] Interaction geometries and energies of hydrogen bonds to C=O and C=S acceptors: a comparative study P. A. Wood, E. Pidcock and F. H. Allen Synopsis: It is shown that hydrogen bonds from O-H and N-H donors to the S acceptors of thioureas and thioamides are relatively longer (by ~ 0.25 AA) and weaker (by ~ 12 kJ mol^-1) than hydrogen bonds to the analogous O-acceptor compounds. Online 10 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 497-503 [ doi:10.1107/S0108768108018272 ] Role of the gauche effect and local 1,3-dipole-dipole interactions in stabilizing an unusual conformation of tartarodinitriles U. Rychlewska, N. Wascinska, B. Warzajtis and J. Gawronski Synopsis: X-ray and NMR studies of meso and chiral tartarodinitriles reveal their diverse conformational preferences compared with tartrates and NH-tartramides, and point to the gauche effects, local dipolar and strong intermolecular interactions as structure determining factors. Online 17 July 2008 ----------------------------------------------------------------- Acta Cryst. (2008). B64, 504-514 [ doi:10.1107/S0108768108019149 ] Hydrogen-bond motifs in the crystals of hydrophobic amino acids L. Fabian, J. A. Chisholm, P. T. A. Galek, W. D. S. Motherwell and N. Feeder Synopsis: A new computer program to search for hydrogen-bond motifs has been developed and used to identify frequent ring and chain motifs in amino-acid crystal structures. Online 17 July 2008 ----------------------------------------------------------------- short communications ----------------------------------------------------------------- Acta Cryst. (2008). B64, 515-518 [ doi:10.1107/S0108768108015309 ] On the correlations between the polyhedron eccentricity parameters and the bond-valence sums for the cations with one lone electron pair V. Sidey Synopsis: The applicability of the Wang-Liebau polyhedron eccentricity parameter in the bond-valence model has been found to be doubtful: the correlations between the values of the polyhedron eccentricity parameters and the bond-valence sums calculated for the cations with one lone electron pair are probably an artifact of the poorly determined bond-valence parameters. Online 10 July 2008 ----------------------------------------------------------------- addenda and errata ----------------------------------------------------------------- [Open access] Acta Cryst. (2008). B64, 519 [ doi:10.1107/S0108768108017497 ] Charge-density studies of energetic materials: CL-20 and FOX-7. Corrigendum A. Meents, B. Dittrich, S. K. J. Johnas, V. Thome and E. F. Weckert Synopsis: A corrigendum to the paper by Meents et al. (2008), Acta Cryst. B64, 42-49. Online 17 July 2008 -----------------------------------------------------------------