(IUCr) Contents for Acta Crystallographica Section B Vol. 61 Part 2 (April 2005)

Acta Cryst. (2005). B61, 129-132 [ doi:10.1107/S0108768105005240 ]

On the structure of aragonite

E. N. Caspi, B. Pokroy, P. L. Lee, J. P. Quintana and E. Zolotoyabko

Synopsis: The structure of geological aragonite was revised using high-resolution X-ray diffraction on synchrotron beamline. The data obtained unambiguously confirm that pure aragonite crystals have orthorhombic symmetry.

Online 16 March 2005

Acta Cryst. (2005). B61, 133-136 [ doi:10.1107/S0108768105003629 ]

On the structure of lithium peroxide, Li₂O₂

L. G. Cota and P. de la Mora

Synopsis: On the basis of space-group reanalysis and high-quality DFT calculations, a new, refined crystal structure for lithium peroxide, Li₂O₂, is proposed. Energetic arguments help to question the validity of one of the two previously reported structures, accepted since 1953.

Online 16 March 2005

Acta Cryst. (2005). B61, 137-144 [ doi:10.1107/S0108768104033919 ]

On the crystal structure of Cr₂N precipitates in high-nitrogen austenitic stainless steel

T.-H. Lee, C.-S. Oh, H. N. Han, C. G. Lee, S.-J. Kim and S. Takaki

Synopsis: The crystal structure of Cr₂N precipitates was confirmed to be trigonal and was characterized by three sets of superlattice reflections. The occupation probability function describing the distribution of nitrogen was derived based on the superlattice reflections obtained in SAD patterns.

Online 16 March 2005

Acta Cryst. (2005). B61, 145-153 [ doi:10.1107/S0108768105001655 ]

Incommensurate crystallographic shear structure of Ba_xBi_2 - 2xTi_4 - xO_{11 - 4x} (x = 0.275)

Y. Michiue, A. Yamamoto, M. Onoda, A. Sato, T. Akashi, H. Yamane and T. Goto

Synopsis: A new incommensurate structure of Ba_xBi_2 - 2xTi_4 - xO_{11 - 4x} (x = 0.275) has been determined. The aperiodic insertion of domain boundaries by the crystallographic shear (CS) operation is defined by the four-dimensional formalism.

Online 16 March 2005

Acta Cryst. (2005). B61, 154-159 [ doi:10.1107/S0108768105001667 ]

Structure and microstructure of hexagonal Ba₃Ti₂RuO₉ by electron diffraction and microscopy

C. Maunders, J. Etheridge, N. Wright and H. J. Whitfield

Synopsis: The crystal structure and microstructure of the hexagonal perovskite Ba₃Ti₂RuO₉ have been refined using convergent-beam electron diffraction and high-resolution electron microscopy.

Online 16 March 2005

Acta Cryst. (2005). B61, 160-163 [ doi:10.1107/S0108768105003186 ]

Structure of toluene6.4-ZSM-5 and the toluene disproportionation reaction on ZSM-5

K. Nishi, A. Hidaka and Y. Yokomori

Synopsis: We have investigated the structure of toluene6.4-ZSM-5 by X-ray single-crystal diffraction and have shown the toluene disproportionation reaction on ZSM-5 zeolite.

Online 16 March 2005

Acta Cryst. (2005). B61, 164-173 [ doi:10.1107/S010876810403294X ]

Three differently coloured concomitant polymorphs: synthesis, structure and packing analysis of (4-(3',5'-dimethyl-1H-pyrazol-1'-yl)-6-methyl-2-phenylpyrimidine)dichlorocopper(II)

E. V. Peresypkina, M. B. Bushuev, A. V. Virovets, V. P. Krivopalov, L. G. Lavrenova and S. V. Larionov

Synopsis: A method of estimating the efficiency of [pi] - [pi] stacking using the Voronoi-Dirichlet partition of crystal space was demonstrated using three polymorphs of the novel compound (4-(3',5'-dimethyl-1H-pyrazol-1'-yl)-6-methyl-2-phenylpyrimidine)dichlorocopper(II).

Online 16 March 2005

Acta Cryst. (2005). B61, 174-184 [ doi:10.1107/S0108768105002247 ]

Packing and molecular shape: layers of centred hexagons as a guiding principle

N. Braun and G. Huttner

Synopsis: From the 112 993 structures containing one residue per cell approximately a third form a packing which may be described as composed of stacks of layers of centred hexagons. The probability of this kind of packing and the density of packing are correlated with the shape of the second moment ellipsoids (ellipsoids of moments of inertia) of the respective molecules.

Online 16 March 2005

Acta Cryst. (2005). B61, 185-191 [ doi:10.1107/S0108768105000455 ]

Structure determination of the stable anhydrous phase of -lactose from X-ray powder diffraction

C. Platteau, J. Lefebvre, F. Affouard, J.-F. Willart, P. Derollez and F. Mallet

Synopsis: The crystal structure of the stable anhydrous form of [alpha] -lactose is solved ab initio at room temperature from X-ray powder diffraction patterns and the minimization of crystalline energy. The Monte-Carlo simulated annealing method is used, followed by Rietveld refinements with geometric soft restraints on bond lengths and bond angles.

Online 16 March 2005

Acta Cryst. (2005). B61, 192-199 [ doi:10.1107/S0108768105006075 ]

Structural characterization of [1,4]diazepino[6,5-b]indoles by powder diffraction

S. Y. Ryabova, N. A. Rastorgueva, E. J. Sonneveld, R. Peschar, H. Schenk, V. A. Tafeenko, L. A. Aslanov and V. V. Chernyshev

Synopsis: The crystal structures of six [1,4]diazepino[6,5-b]indole derivatives and three intermediates have been determined and characterized using laboratory X-ray powder diffraction data.

Online 16 March 2005

Acta Cryst. (2005). B61, 200-206 [ doi:10.1107/S0108768104034007 ]

Determination of the low-temperature structure of hexamethylbenzene

J. A. Stride

Synopsis: The structure of hexamethylbenzene below the first-order phase transition at 117 K has been obtained using neutron powder diffraction, over 70 years after the first report of the room-temperature X-ray crystal structure of this ubiquitous laboratory chemical. The low-temperature structure may be considered as a high-density modification of the room-temperature structure, resulting from decreased thermally induced disorder.

Online 16 March 2005

Acta Cryst. (2005). B61, 207-217 [ doi:10.1107/S0108768105004106 ]

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in -cyclodextrin and heptakis(2,3,6-tri-O-methyl)--cyclodextrin

F. Tsorteki, K. Bethanis, N. Pinotsis, P. Giastas and D. Mentzafos

Synopsis: The X-ray crystal structure analyses of two crystals of 4-chlorophenoxyacetic acid encapsulated in [beta] -cyclodextrin and heptakis(2,3,6-tri-O-methyl)- [beta] -cyclodextrin was reported. It is the fifth part of a series concerning the inclusion compounds of plant growth regulators in cyclodextrins.

Online 16 March 2005

Acta Cryst. (2005). B61, 218-226 [ doi:10.1107/S0108768105004076 ]

A helical structure with Z' = 10

X. Hao, J. Chen, A. Cammers, S. Parkin and C. P. Brock

Synopsis: A very unusual high Z' structure with no important crystallographic pseudosymmetry has been determined.

Online 16 March 2005

Acta Cryst. (2005). B61, 227-237 [ doi:10.1107/S0108768105004234 ]

Isomeric N-(iodophenyl)nitrophthalimides: interplay of C-HO hydrogen bonds, iodonitro and iodocarbonyl interactions, and aromatic stacking interactions

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

Synopsis: Five isomeric N-(iodophenyl)-nitrophthalimides all exhibit a different range of intermolecular interactions, including C-HO(nitro) and C-HO(carbonyl) hydrogen bonds, two- and three-centre iodonitro and two-centre iodocarbonyl interactions, and aromatic [pi] [pi] stacking interactions; all five isomers have qualitatively different supramolecular structures.

Online 16 March 2005

Acta Crystallographica Section B

Structural Science

Volume 61, Part 2 (April 2005)

research papers

On the structure of aragonite

E. N. Caspi, B. Pokroy, P. L. Lee, J. P. Quintana and E. Zolotoyabko

On the structure of lithium peroxide, Li₂O₂

L. G. Cota and P. de la Mora

On the crystal structure of Cr₂N precipitates in high-nitrogen austenitic stainless steel

T.-H. Lee, C.-S. Oh, H. N. Han, C. G. Lee, S.-J. Kim and S. Takaki

Incommensurate crystallographic shear structure of Ba_xBi_2 - 2xTi_4 - xO_{11 - 4x} (x = 0.275)

Y. Michiue, A. Yamamoto, M. Onoda, A. Sato, T. Akashi, H. Yamane and T. Goto

Structure and microstructure of hexagonal Ba₃Ti₂RuO₉ by electron diffraction and microscopy

C. Maunders, J. Etheridge, N. Wright and H. J. Whitfield

Structure of toluene6.4-ZSM-5 and the toluene disproportionation reaction on ZSM-5

K. Nishi, A. Hidaka and Y. Yokomori

Three differently coloured concomitant polymorphs: synthesis, structure and packing analysis of (4-(3',5'-dimethyl-1H-pyrazol-1'-yl)-6-methyl-2-phenylpyrimidine)dichlorocopper(II)

E. V. Peresypkina, M. B. Bushuev, A. V. Virovets, V. P. Krivopalov, L. G. Lavrenova and S. V. Larionov

Packing and molecular shape: layers of centred hexagons as a guiding principle

N. Braun and G. Huttner

Structure determination of the stable anhydrous phase of -lactose from X-ray powder diffraction

C. Platteau, J. Lefebvre, F. Affouard, J.-F. Willart, P. Derollez and F. Mallet

Structural characterization of [1,4]diazepino[6,5-b]indoles by powder diffraction

S. Y. Ryabova, N. A. Rastorgueva, E. J. Sonneveld, R. Peschar, H. Schenk, V. A. Tafeenko, L. A. Aslanov and V. V. Chernyshev

Determination of the low-temperature structure of hexamethylbenzene

J. A. Stride

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in -cyclodextrin and heptakis(2,3,6-tri-O-methyl)--cyclodextrin

F. Tsorteki, K. Bethanis, N. Pinotsis, P. Giastas and D. Mentzafos

A helical structure with Z' = 10

X. Hao, J. Chen, A. Cammers, S. Parkin and C. P. Brock

Isomeric N-(iodophenyl)nitrophthalimides: interplay of C-HO hydrogen bonds, iodonitro and iodocarbonyl interactions, and aromatic stacking interactions

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

related papers

Acta Crystallographica Section B

Structural Science

Volume 61, Part 2 (April 2005)

research papers

On the structure of aragonite

E. N. Caspi, B. Pokroy, P. L. Lee, J. P. Quintana and E. Zolotoyabko

On the structure of lithium peroxide, Li2O2

L. G. Cota and P. de la Mora

On the crystal structure of Cr2N precipitates in high-nitrogen austenitic stainless steel

T.-H. Lee, C.-S. Oh, H. N. Han, C. G. Lee, S.-J. Kim and S. Takaki

Incommensurate crystallographic shear structure of BaxBi2 - 2xTi4 - xO11 - 4x (x = 0.275)

Y. Michiue, A. Yamamoto, M. Onoda, A. Sato, T. Akashi, H. Yamane and T. Goto

Structure and microstructure of hexagonal Ba3Ti2RuO9 by electron diffraction and microscopy

C. Maunders, J. Etheridge, N. Wright and H. J. Whitfield

Structure of toluene6.4-ZSM-5 and the toluene disproportionation reaction on ZSM-5

K. Nishi, A. Hidaka and Y. Yokomori

Three differently coloured concomitant polymorphs: synthesis, structure and packing analysis of (4-(3',5'-dimethyl-1H-pyrazol-1'-yl)-6-methyl-2-phenylpyrimidine)dichlorocopper(II)

E. V. Peresypkina, M. B. Bushuev, A. V. Virovets, V. P. Krivopalov, L. G. Lavrenova and S. V. Larionov

Packing and molecular shape: layers of centred hexagons as a guiding principle

N. Braun and G. Huttner

Structure determination of the stable anhydrous phase of -lactose from X-ray powder diffraction

C. Platteau, J. Lefebvre, F. Affouard, J.-F. Willart, P. Derollez and F. Mallet

Structural characterization of [1,4]diazepino[6,5-b]indoles by powder diffraction

S. Y. Ryabova, N. A. Rastorgueva, E. J. Sonneveld, R. Peschar, H. Schenk, V. A. Tafeenko, L. A. Aslanov and V. V. Chernyshev

Determination of the low-temperature structure of hexamethylbenzene

J. A. Stride

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in -cyclodextrin and heptakis(2,3,6-tri-O-methyl)--cyclodextrin

F. Tsorteki, K. Bethanis, N. Pinotsis, P. Giastas and D. Mentzafos

A helical structure with Z' = 10

X. Hao, J. Chen, A. Cammers, S. Parkin and C. P. Brock

Isomeric N-(iodophenyl)nitrophthalimides: interplay of C-HO hydrogen bonds, iodonitro and iodocarbonyl interactions, and aromatic stacking interactions

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

related papers

On the structure of lithium peroxide, Li₂O₂

On the crystal structure of Cr₂N precipitates in high-nitrogen austenitic stainless steel

Incommensurate crystallographic shear structure of Ba_xBi_2 - 2xTi_4 - xO_{11 - 4x} (x = 0.275)

Structure and microstructure of hexagonal Ba₃Ti₂RuO₉ by electron diffraction and microscopy