(IUCr) Contents for Acta Crystallographica Section B Vol. 60 Part 4 (August 2004)

Acta Cryst. (2004). B60, 359-368 [ doi:10.1107/S0108768104009437 ]

Electron density and electrostatic potential of KMnF₃: a phase-transition study

Y. Ivanov, T. Nimura and K. Tanaka

Synopsis: Three accurate X-ray diffraction experiments were carried out to determine the temperature dependence of the electron density in cubic perovskite KMnF₃, from room temperature to just above that of the phase transition to the tetragonal structure (186 K), and to correlate the parameters of the critical points with the phase-transition mechanism.

Online 19 July 2004

Acta Cryst. (2004). B60, 369-374 [ doi:10.1107/S0108768104011735 ]

Variation of large-scale regularity in modulated structures of Ca₂CoSi₂O₇ studied by a simulation method

K. Kusaka, K. Hagiya, M. Ohmasa and K. Iishi

Synopsis: Simulation studies on changes in structure with a variation in q revealed that various large-scale regularities larger than the modulation wavelengths are formed in the incommensurate structures of Ca₂CoSi₂O₇.

Online 19 July 2004

Acta Cryst. (2004). B60, 375-381 [ doi:10.1107/S0108768104012881 ]

Structure of a high-pressure phase of vanadium pentoxide, -V₂O₅

V. P. Filonenko, M. Sundberg, P.-E. Werner and I. P. Zibrov

Synopsis: The structure of a high-pressure phase of vanadium pentoxide, [beta] -V₂O₅, has been studied by X-ray and neutron powder diffraction and HRTEM. Structural relationships between [alpha] - and [beta] -V₂O₅, and between [beta] -V₂O₅- and B-Ta₂O₅-type structures are discussed.

Online 19 July 2004

Acta Cryst. (2004). B60, 382-387 [ doi:10.1107/S0108768104013096 ]

Li₃₊V₆O₁₃: a short-range-ordered lithium insertion mechanism

J. Höwing, T. Gustafsson and J. O. Thomas

Synopsis: The structures of Li₃V₆O₁₃ and Li₃₊V₆O₁₃, [delta] [asymptotically equal to] 0.3, have been determined by single-crystal X-ray diffraction. A mechanism is proposed for lithium insertion in the composition range Li₃V₆O₁₃-Li₆V₆O₁₃.

Online 19 July 2004

Acta Cryst. (2004). B60, 388-405 [ doi:10.1107/S010876810401393X ]

Synchrotron X-ray and ab initio studies of -Si₃N₄

D. du Boulay, N. Ishizawa, T. Atake, V. Streltsov, K. Furuya and F. Munakata

Synopsis: The redistribution of bonding electron density in SiN was studied by means of three synchrotron X-ray experiments and a theoretical plane-wave study.

Online 19 July 2004

Acta Cryst. (2004). B60, 406-415 [ doi:10.1107/S0108768104010365 ]

Structural manifestations of proton transfer in complexes of 2,6-dichlorophenols with pyridines

I. Majerz and A. Koll

Synopsis: The experimental results on X-ray structure determination in complexes of 2,6-dichlorophenols with different pyridines are analyzed in relation to the degree of proton transfer. Theoretical trends are described on the basis of B2LYP/6-31G(d,p) calculations.

Online 19 July 2004

Acta Cryst. (2004). B60, 416-423 [ doi:10.1107/S0108768104010699 ]

Bis(1-chloro-2,2,4,4-tetramethyl-3-oxocyclobutan-1-yl)pentasulfane: an occupancy modulated structure

A. D. Rae, A. Linden, A. Majchrzak, G. Mloston and H. Heimgartner

Synopsis: The title compound crystallizes in the space group P2₁/n and may be described by a partial ordering of a 1:1 disordered P2₁/a parent structure with the c axis halved. The structure can be redescribed as 0.732 (1) of an ordered P2₁/n structure and 0.268 (1) of a 1:1 disordered P2₁/a structure with atom positions in the asymmetric unit that are significantly non-identical.

Online 19 July 2004

Acta Cryst. (2004). B60, 424-432 [ doi:10.1107/S0108768104014442 ]

Analysis of the less common hydrogen bonds involving ester oxygen sp³ atoms as acceptors in the crystal structures of small organic molecules

K. Molcanov, B. Kojic-Prodic and N. Raos

Synopsis: Experimental evidence of the Osp³ ester acceptor function in hydrogen bonds extracted from the Cambridge Structural Database is shown. Geometrical data are analysed in view of known hydrogen-bond criteria. The observed data revealing the acceptor function of the Osp³ ester are in agreement with the ab initio-based energy calculations performed by Lommerse et al. [(1997), J. Comput. Chem. 18, 757-774].

Online 19 July 2004

Acta Cryst. (2004). B60, 433-437 [ doi:10.1107/S0108768104013047 ]

Rigid backbone moiety of KNI-272, a highly selective HIV protease inhibitor: methanol, acetone and dimethylsulfoxide solvated forms of 3-[3-benzyl-2-hydroxy-9-(isoquinolin-5-yloxy)-6-methylsulfanylmethyl-5,8-dioxo-4,7-diazanonanoyl]-N-tert-butyl-1,3-thiazolidine-4-carboxamide

M. Doi, T. Kimura, T. Ishida and Y. Kiso

Synopsis: Crystals of KNI-272, a highly selective HIV protease inhibitor, were grown in three different solvent systems. The local conformations around the hydroxymethylcarbonyl moiety were similar in all three forms with a remarkable similarity in the C-terminal region. Their conformational characteristics of the uncomplexed forms resembled those of the inhibitor within the KNI-272-HIV protease complex. This suggests that the structure of the C-terminal region of KNI-272 is rigid or very stable.

Online 19 July 2004

Acta Cryst. (2004). B60, 438-446 [ doi:10.1107/S0108768104012686 ]

2-Hydroxyisophthalic acid: hydrogen-bonding patterns in the monohydrate and the tetraphenylphosphonium salt. An instance of dramatic acidity enhancement by symmetric, internally hydrogen-bonded anion stabilization

S. Bawa, M. L. Coté, P. Dubois, R. A. Lalancette and H. W. Thompson

Synopsis: The title phenolic diacid presents an elaborate two-dimensional hydrogen-bonding pattern, in which its water of monohydration is intimately involved. The title compound's high phenol acidity is reflected in its monoanionic tetraphenylphosphonium salt, where charge is stabilized on the phenol oxygen by symmetrical hydrogen-bond donation from both ortho groups.

Online 19 July 2004

Acta Cryst. (2004). B60, 447-452 [ doi:10.1107/S0108768104012698 ]

Sizes of molecules in organic crystals: the Voronoi-Dirichlet approach

I. A. Baburin and V. A. Blatov

Synopsis: The volumes of more than 100 000 molecules in organic crystals have been calculated using the Voronoi-Dirichlet procedure. It is shown in this report that the average volumes are nearly equal to the corresponding values in homomolecular crystals and the reasons for the variations in molecular sizes are discussed.

Online 19 July 2004

Acta Cryst. (2004). B60, 453-460 [ doi:10.1107/S0108768104014375 ]

Ab initio structure determination of the hygroscopic anhydrous form of -lactose by powder X-ray diffraction

C. Platteau, J. Lefebvre, F. Affouard and P. Derollez

Synopsis: The crystal structure of the hygroscopic anhydrous form of [alpha] -lactose is solved ab initio at 293 K from powder X-ray diffraction data. A real-space method (Monte Carlo simulated annealing), Rietveld refinements with geometric soft restraints, and energy minimization calculations have been used.

Online 19 July 2004

Acta Cryst. (2004). B60, 461-471 [ doi:10.1107/S0108768104010912 ]

Supramolecular structures of substituted ,'-trehalose derivatives

T. C. Baddeley, I. G. Davidson, C. Glidewell, J. N. Low, J. M. S. Skakle and J. L. Wardell

Synopsis: Hard and soft hydrogen bonds in substituted trehalose derivatives generate supramolecular structures in one, two and three dimensions.

Online 19 July 2004

Acta Cryst. (2004). B60, 472-480 [ doi:10.1107/S0108768104012017 ]

Isomeric iodo-N-(nitrobenzyl)anilines: interplay of hard and soft hydrogen bonds, iodonitro interactions and aromatic stacking interactions

C. Glidewell, J. N. Low, J. M. S. Skakle, S. M. S. V. Wardell and J. L. Wardell

Synopsis: Iodo-N-(nitrobenzyl)anilines, O₂NC₆H₄CH₂NHC₆H₄I, can exhibit hydrogen bonds of four types, N-HO, C-HO, N-H [pi] (arene) and C-H [pi] (arene), as well as iodonitro and aromatic [pi] [pi] stacking interactions. The resulting supramolecular structures can be one-, two- or three-dimensional.

Online 19 July 2004

Acta Cryst. (2004). B60, 481-489 [ doi:10.1107/S0108768104013564 ]

Structural features controlling the binding of -carbolines to the benzodiazepine receptor

V. Ferretti, P. Gilli and P. A. Borea

Synopsis: A structural comparison study by superimposition techniques, integrated by the analysis of affinity data, is presented in this paper in order to obtain a deeper insight into the structure-activity relationships in [beta] -carbolines.

Online 19 July 2004

addenda and errata

Acta Cryst. (2004). B60, 490 [ doi:10.1107/S010876810401287X ]

New bond-valence parameters for lanthanides. Addendum

A. Trzesowska, R. Kruszynski and T. J. Bartczak

Synopsis: An addendum to the paper by Trzesowska et al. (2004). Acta Cryst. B60, 174-178.

Online 19 July 2004

Acta Crystallographica Section B

Structural Science

Volume 60, Part 4 (August 2004)

research papers

Electron density and electrostatic potential of KMnF₃: a phase-transition study

Y. Ivanov, T. Nimura and K. Tanaka

Variation of large-scale regularity in modulated structures of Ca₂CoSi₂O₇ studied by a simulation method

K. Kusaka, K. Hagiya, M. Ohmasa and K. Iishi

Structure of a high-pressure phase of vanadium pentoxide, -V₂O₅

V. P. Filonenko, M. Sundberg, P.-E. Werner and I. P. Zibrov

Li₃₊V₆O₁₃: a short-range-ordered lithium insertion mechanism

J. Höwing, T. Gustafsson and J. O. Thomas

Synchrotron X-ray and ab initio studies of -Si₃N₄

D. du Boulay, N. Ishizawa, T. Atake, V. Streltsov, K. Furuya and F. Munakata

Structural manifestations of proton transfer in complexes of 2,6-dichlorophenols with pyridines

I. Majerz and A. Koll

Bis(1-chloro-2,2,4,4-tetramethyl-3-oxocyclobutan-1-yl)pentasulfane: an occupancy modulated structure

A. D. Rae, A. Linden, A. Majchrzak, G. Mloston and H. Heimgartner

Analysis of the less common hydrogen bonds involving ester oxygen sp³ atoms as acceptors in the crystal structures of small organic molecules

K. Molcanov, B. Kojic-Prodic and N. Raos

Rigid backbone moiety of KNI-272, a highly selective HIV protease inhibitor: methanol, acetone and dimethylsulfoxide solvated forms of 3-[3-benzyl-2-hydroxy-9-(isoquinolin-5-yloxy)-6-methylsulfanylmethyl-5,8-dioxo-4,7-diazanonanoyl]-N-tert-butyl-1,3-thiazolidine-4-carboxamide

M. Doi, T. Kimura, T. Ishida and Y. Kiso

2-Hydroxyisophthalic acid: hydrogen-bonding patterns in the monohydrate and the tetraphenylphosphonium salt. An instance of dramatic acidity enhancement by symmetric, internally hydrogen-bonded anion stabilization

S. Bawa, M. L. Coté, P. Dubois, R. A. Lalancette and H. W. Thompson

Sizes of molecules in organic crystals: the Voronoi-Dirichlet approach

I. A. Baburin and V. A. Blatov

Ab initio structure determination of the hygroscopic anhydrous form of -lactose by powder X-ray diffraction

C. Platteau, J. Lefebvre, F. Affouard and P. Derollez

Supramolecular structures of substituted ,'-trehalose derivatives

T. C. Baddeley, I. G. Davidson, C. Glidewell, J. N. Low, J. M. S. Skakle and J. L. Wardell

Isomeric iodo-N-(nitrobenzyl)anilines: interplay of hard and soft hydrogen bonds, iodonitro interactions and aromatic stacking interactions

C. Glidewell, J. N. Low, J. M. S. Skakle, S. M. S. V. Wardell and J. L. Wardell

Structural features controlling the binding of -carbolines to the benzodiazepine receptor

V. Ferretti, P. Gilli and P. A. Borea

addenda and errata

New bond-valence parameters for lanthanides. Addendum

A. Trzesowska, R. Kruszynski and T. J. Bartczak

Acta Crystallographica Section B

Structural Science

Volume 60, Part 4 (August 2004)

research papers

Electron density and electrostatic potential of KMnF3: a phase-transition study

Y. Ivanov, T. Nimura and K. Tanaka

Variation of large-scale regularity in modulated structures of Ca2CoSi2O7 studied by a simulation method

K. Kusaka, K. Hagiya, M. Ohmasa and K. Iishi

Structure of a high-pressure phase of vanadium pentoxide, -V2O5

V. P. Filonenko, M. Sundberg, P.-E. Werner and I. P. Zibrov

Li3+V6O13: a short-range-ordered lithium insertion mechanism

J. Höwing, T. Gustafsson and J. O. Thomas

Synchrotron X-ray and ab initio studies of -Si3N4

D. du Boulay, N. Ishizawa, T. Atake, V. Streltsov, K. Furuya and F. Munakata

Structural manifestations of proton transfer in complexes of 2,6-dichlorophenols with pyridines

I. Majerz and A. Koll

Bis(1-chloro-2,2,4,4-tetramethyl-3-oxocyclobutan-1-yl)pentasulfane: an occupancy modulated structure

A. D. Rae, A. Linden, A. Majchrzak, G. Mloston and H. Heimgartner

Analysis of the less common hydrogen bonds involving ester oxygen sp3 atoms as acceptors in the crystal structures of small organic molecules

K. Molcanov, B. Kojic-Prodic and N. Raos

Rigid backbone moiety of KNI-272, a highly selective HIV protease inhibitor: methanol, acetone and dimethylsulfoxide solvated forms of 3-[3-benzyl-2-hydroxy-9-(isoquinolin-5-yloxy)-6-methylsulfanylmethyl-5,8-dioxo-4,7-diazanonanoyl]-N-tert-butyl-1,3-thiazolidine-4-carboxamide

M. Doi, T. Kimura, T. Ishida and Y. Kiso

2-Hydroxyisophthalic acid: hydrogen-bonding patterns in the monohydrate and the tetraphenylphosphonium salt. An instance of dramatic acidity enhancement by symmetric, internally hydrogen-bonded anion stabilization

S. Bawa, M. L. Coté, P. Dubois, R. A. Lalancette and H. W. Thompson

Sizes of molecules in organic crystals: the Voronoi-Dirichlet approach

I. A. Baburin and V. A. Blatov

Ab initio structure determination of the hygroscopic anhydrous form of -lactose by powder X-ray diffraction

C. Platteau, J. Lefebvre, F. Affouard and P. Derollez

Supramolecular structures of substituted ,'-trehalose derivatives

T. C. Baddeley, I. G. Davidson, C. Glidewell, J. N. Low, J. M. S. Skakle and J. L. Wardell

Isomeric iodo-N-(nitrobenzyl)anilines: interplay of hard and soft hydrogen bonds, iodonitro interactions and aromatic stacking interactions

C. Glidewell, J. N. Low, J. M. S. Skakle, S. M. S. V. Wardell and J. L. Wardell

Structural features controlling the binding of -carbolines to the benzodiazepine receptor

V. Ferretti, P. Gilli and P. A. Borea

addenda and errata

New bond-valence parameters for lanthanides. Addendum

A. Trzesowska, R. Kruszynski and T. J. Bartczak

Electron density and electrostatic potential of KMnF₃: a phase-transition study

Variation of large-scale regularity in modulated structures of Ca₂CoSi₂O₇ studied by a simulation method

Structure of a high-pressure phase of vanadium pentoxide, -V₂O₅

Li₃₊V₆O₁₃: a short-range-ordered lithium insertion mechanism

Synchrotron X-ray and ab initio studies of -Si₃N₄

Analysis of the less common hydrogen bonds involving ester oxygen sp³ atoms as acceptors in the crystal structures of small organic molecules