(IUCr) Contents for Acta Crystallographica Section B Vol. 57 Part 2 (April 2001)

Acta Cryst. (2001). B57, 113-118 [ doi:10.1107/S0108768100018887 ]

Anisotropic thermal expansion of potassium dinitramide: a variable-temperature crystallographic study

M. J. Hardie, A. Martin, A. A. Pinkerton and E. A. Zhurova

Synopsis: The structure of potassium dinitramide (KDN) has been refined from X-ray diffraction data in the temperature range 85-298 K. The thermal expansion is significantly anisotropic and correlated to the atomic displacement parameters. A rigid-body analysis of the dinitramide anion was carried out. The variation of thermal motion with temperature indicates anharmonicity in the mean field potential.

Online April 2001

Acta Cryst. (2001). B57, 119-127 [ doi:10.1107/S0108768100016979 ]

Quantifying distortion from ideal closest-packing in a crystal structure with analysis and application

R. M. Thompson and R. T. Downs

Synopsis: An isotropic distortion parameter has been defined that quantifies the departure of the anion skeleton of a crystal from ideal closest-packing. Analysis of the variation in this parameter for a variety of rock-forming minerals at various temperatures and pressures elucidates the important role of anion-anion interactions during expansion and compression.

Online April 2001

Acta Cryst. (2001). B57, 128-135 [ doi:10.1107/S0108768100017353 ]

Synchrotron X-ray analysis of the electron density in CoF₂ and ZnF₂

N. J. O'Toole and V. A. Streltsov

Synopsis: Structural, multipole and orbital analyses of the electron density in the rutile-type compounds CoF₂ and ZnF₂ have been performed using synchrotron X-ray data.

Online April 2001

Acta Cryst. (2001). B57, 136-141 [ doi:10.1107/S0108768100019923 ]

Synchrotron X-ray study of Er₃Al₅O₁₂ and Yb₃Al₅O₁₂ garnets

B. Etschmann, V. Streltsov, N. Ishizawa and E. N. Maslen

Synopsis: Structure factors for the Er₃Al₅O₁₂ and Yb₃Al₅O₁₂ garnets were measured with synchrotron X-radiation at room temperature. Approximate difference electron density symmetry around the rare-earth atoms was found to reflect that of the cation geometry, emphasizing the importance of second nearest-neighbor interactions.

Online April 2001

Acta Cryst. (2001). B57, 142-150 [ doi:10.1107/S0108768100015597 ]

Characterization of the room-temperature phase of Tl₂MoO₄: crystal structure, symmetry mode analysis and second-harmonic generation measurements

K. Friese, M. I. Aroyo, C. L. Folcia, G. Madariaga and T. Breczewski

Synopsis: The structure of Tl₂MoO₄ at 293 K has been refined and compared to the structure at 350 K. Second-harmonic generation measurements and symmetry mode analysis have been performed.

Online April 2001

Acta Cryst. (2001). B57, 151-156 [ doi:10.1107/S0108768100016621 ]

Reversible phase transitions in Na₂S under pressure: a comparison with the cation array in Na₂SO₄

A. Vegas, A. Grzechnik, K. Syassen, I. Loa, M. Hanfland and M. Jansen

Synopsis: The antifluorite Na₂S, disodium sulfide, undergoes, under pressure, two phase transitions adopting the anticotunnite and the Ni₂In-type structures. The latter is just the structure which presents the cation array in the high-temperature phases of Na₂SO₄. An equivalence between oxidation and pressure is established, in the sense that both stabilize the Ni₂In-type structure as if the Na and S atoms were recognized in spite of being embedded in an oxygen matrix.

Online April 2001

Acta Cryst. (2001). B57, 157-162 [ doi:10.1107/S0108768100018917 ]

A novel perovskite-like Ta-bronze KTa_1+zO₃: preparation, stoichiometry, conductivity and crystal structure studies

A. Arakcheeva, G. Chapuis, V. Grinevitch and V. Shamray

Synopsis: KTa_1 + zO₃, an oxide bronze, has been synthesized by electrolytic crystallization. The high-resolution anharmonic crystal structure refinement reveals the presence of Ta₂ dumb-bells in the KTaO₃ matrix, which explain the semiconductor property.

Online April 2001

Acta Cryst. (2001). B57, 163-177 [ doi:10.1107/S0108768100018188 ]

Systematic ab initio study of the compressibility of silicate garnets

V. Milman, E. V. Akhmatskaya, R. H. Nobes, B. Winkler, C. J. Pickard and J. A. White

Synopsis: The structures of a number of cubic silicate garnets at ambient pressure and under compression have been investigated using first-principles pseudopotential calculations.

Online April 2001

Acta Cryst. (2001). B57, 178-183 [ doi:10.1107/S0108768100015603 ]

Structure determination of two intercalated compounds VOPO₄·(CH₂)₄O and VOPO₄·OH-(CH₂)₂-O-(CH₂)₂-OH; synchrotron powder diffraction and molecular modelling

K. Goubitz, P. Capková, K. Melánová, W. Molleman and H. Schenk

Synopsis: The structure of two intercalated compounds VOPO₄-thf and VOPO₄-DEG were determined by a combination of high-resolution synchrotron powder diffraction and molecular modelling. Both intercalates exhibit the same type of orientational disorder as observed in VOPO₄ intercalated with water.

Online April 2001

Acta Cryst. (2001). B57, 184-189 [ doi:10.1107/S0108768100018905 ]

Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: combined use of direct methods and the Monte Carlo method

Y. Tanahashi, H. Nakamura, S. Yamazaki, Y. Kojima, H. Saito, T. Ida and H. Toraya

Synopsis: The crystal structure of the monoclinic form of 2,2-dihydroxymethylbutanoic acid (C₆H₁₂O₄) has been determined ab initio using synchrotron radiation powder diffraction data. A partial direct method soluition was completed using Monte Carlo techniques.

Online April 2001

Acta Cryst. (2001). B57, 190-200 [ doi:10.1107/S0108768100015494 ]

Patterns of soft C-HO hydrogen bonding in diaryl sulfones

C. Glidewell, W. T. A. Harrison, J. N. Low, J. G. Sime and J. L. Wardell

Synopsis: Soft C-HO hydrogen bonds link molecules of substituted diaryl sulfones into aggregates which can be zero-, one-, two- or three-dimensional.

Online April 2001

Acta Cryst. (2001). B57, 201-212 [ doi:10.1107/S010876810001853X ]

Salts of 3,5-dinitrobenzoic acid with organic diamines: hydrogen-bonded supramolecular structures in one, two and three dimensions

C. J. Burchell, C. Glidewell, A. J. Lough and G. Ferguson

Synopsis: 3,5-Dinitrobenzoic acid forms salt-type 2:1 adducts with a range of organic diamines. The ions are linked into three-component aggregates by N-HO hydrogen bonds, and these aggregates can be further linked by combinations of N-HO and C-HO hydrogen bonds into continuous arrays which may be one-, two- or three-dimensional.

Online April 2001

Acta Cryst. (2001). B57, 213-220 [ doi:10.1107/S010876810001661X ]

Structures of furanosides: geometrical analysis of low-temperature X-ray and neutron crystal structures of five crystalline methyl pentofuranosides

A. Evdokimov, A. J. Gilboa, T. F. Koetzle, W. T. Klooster, A. J. Schultz, S. A. Mason, A. Albinati and F. Frolow

Synopsis: Accurate X-ray and neutron structures of the five crystalline methyl pentofuranosides allow for detailed investigation of furanoside ring geometry.

Online April 2001

Acta Crystallographica Section B

Structural Science

Volume 57, Part 2 (April 2001)

research papers

Anisotropic thermal expansion of potassium dinitramide: a variable-temperature crystallographic study

M. J. Hardie, A. Martin, A. A. Pinkerton and E. A. Zhurova

Quantifying distortion from ideal closest-packing in a crystal structure with analysis and application

R. M. Thompson and R. T. Downs

Synchrotron X-ray analysis of the electron density in CoF₂ and ZnF₂

N. J. O'Toole and V. A. Streltsov

Synchrotron X-ray study of Er₃Al₅O₁₂ and Yb₃Al₅O₁₂ garnets

B. Etschmann, V. Streltsov, N. Ishizawa and E. N. Maslen

Characterization of the room-temperature phase of Tl₂MoO₄: crystal structure, symmetry mode analysis and second-harmonic generation measurements

K. Friese, M. I. Aroyo, C. L. Folcia, G. Madariaga and T. Breczewski

Reversible phase transitions in Na₂S under pressure: a comparison with the cation array in Na₂SO₄

A. Vegas, A. Grzechnik, K. Syassen, I. Loa, M. Hanfland and M. Jansen

A novel perovskite-like Ta-bronze KTa_1+zO₃: preparation, stoichiometry, conductivity and crystal structure studies

A. Arakcheeva, G. Chapuis, V. Grinevitch and V. Shamray

Systematic ab initio study of the compressibility of silicate garnets

V. Milman, E. V. Akhmatskaya, R. H. Nobes, B. Winkler, C. J. Pickard and J. A. White

Structure determination of two intercalated compounds VOPO₄·(CH₂)₄O and VOPO₄·OH-(CH₂)₂-O-(CH₂)₂-OH; synchrotron powder diffraction and molecular modelling

K. Goubitz, P. Capková, K. Melánová, W. Molleman and H. Schenk

Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: combined use of direct methods and the Monte Carlo method

Y. Tanahashi, H. Nakamura, S. Yamazaki, Y. Kojima, H. Saito, T. Ida and H. Toraya

Patterns of soft C-HO hydrogen bonding in diaryl sulfones

C. Glidewell, W. T. A. Harrison, J. N. Low, J. G. Sime and J. L. Wardell

Salts of 3,5-dinitrobenzoic acid with organic diamines: hydrogen-bonded supramolecular structures in one, two and three dimensions

C. J. Burchell, C. Glidewell, A. J. Lough and G. Ferguson

Structures of furanosides: geometrical analysis of low-temperature X-ray and neutron crystal structures of five crystalline methyl pentofuranosides

A. Evdokimov, A. J. Gilboa, T. F. Koetzle, W. T. Klooster, A. J. Schultz, S. A. Mason, A. Albinati and F. Frolow

related papers

Acta Crystallographica Section B

Structural Science

Volume 57, Part 2 (April 2001)

research papers

Anisotropic thermal expansion of potassium dinitramide: a variable-temperature crystallographic study

M. J. Hardie, A. Martin, A. A. Pinkerton and E. A. Zhurova

Quantifying distortion from ideal closest-packing in a crystal structure with analysis and application

R. M. Thompson and R. T. Downs

Synchrotron X-ray analysis of the electron density in CoF2 and ZnF2

N. J. O'Toole and V. A. Streltsov

Synchrotron X-ray study of Er3Al5O12 and Yb3Al5O12 garnets

B. Etschmann, V. Streltsov, N. Ishizawa and E. N. Maslen

Characterization of the room-temperature phase of Tl2MoO4: crystal structure, symmetry mode analysis and second-harmonic generation measurements

K. Friese, M. I. Aroyo, C. L. Folcia, G. Madariaga and T. Breczewski

Reversible phase transitions in Na2S under pressure: a comparison with the cation array in Na2SO4

A. Vegas, A. Grzechnik, K. Syassen, I. Loa, M. Hanfland and M. Jansen

A novel perovskite-like Ta-bronze KTa1+zO3: preparation, stoichiometry, conductivity and crystal structure studies

A. Arakcheeva, G. Chapuis, V. Grinevitch and V. Shamray

Systematic ab initio study of the compressibility of silicate garnets

V. Milman, E. V. Akhmatskaya, R. H. Nobes, B. Winkler, C. J. Pickard and J. A. White

Structure determination of two intercalated compounds VOPO4·(CH2)4O and VOPO4·OH-(CH2)2-O-(CH2)2-OH; synchrotron powder diffraction and molecular modelling

K. Goubitz, P. Capková, K. Melánová, W. Molleman and H. Schenk

Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: combined use of direct methods and the Monte Carlo method

Y. Tanahashi, H. Nakamura, S. Yamazaki, Y. Kojima, H. Saito, T. Ida and H. Toraya

Patterns of soft C-HO hydrogen bonding in diaryl sulfones

C. Glidewell, W. T. A. Harrison, J. N. Low, J. G. Sime and J. L. Wardell

Salts of 3,5-dinitrobenzoic acid with organic diamines: hydrogen-bonded supramolecular structures in one, two and three dimensions

C. J. Burchell, C. Glidewell, A. J. Lough and G. Ferguson

Structures of furanosides: geometrical analysis of low-temperature X-ray and neutron crystal structures of five crystalline methyl pentofuranosides

A. Evdokimov, A. J. Gilboa, T. F. Koetzle, W. T. Klooster, A. J. Schultz, S. A. Mason, A. Albinati and F. Frolow

related papers

Synchrotron X-ray analysis of the electron density in CoF₂ and ZnF₂

Synchrotron X-ray study of Er₃Al₅O₁₂ and Yb₃Al₅O₁₂ garnets

Characterization of the room-temperature phase of Tl₂MoO₄: crystal structure, symmetry mode analysis and second-harmonic generation measurements

Reversible phase transitions in Na₂S under pressure: a comparison with the cation array in Na₂SO₄

A novel perovskite-like Ta-bronze KTa_1+zO₃: preparation, stoichiometry, conductivity and crystal structure studies

Structure determination of two intercalated compounds VOPO₄·(CH₂)₄O and VOPO₄·OH-(CH₂)₂-O-(CH₂)₂-OH; synchrotron powder diffraction and molecular modelling