Forthcoming article in Acta Crystallographica Section A Foundations and Advances
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Acta Crystallographica Section A: Foundations of Crystallography publishes articles reporting fundamental advances in all areas of crystallography in the broadest sense. This includes metacrystals such as photonic or phononic crystals, i.e. structures on the meso- or macroscale that can be studied with crystallographic methods. The central themes are, on the one hand, experimental and theoretical studies of the properties and arrangements of atoms, ions and molecules in condensed matter, periodic, quasiperiodic or amorphous, ideal or real, and, on the other, the theoretical and experimental aspects of the various methods to determine these properties and arrangements. In the case of metacrystals, the focus is on the methods for their creation and on the structure-property relationships for their interaction with classical waves.en-gbCopyright (c) 2014 International Union of CrystallographyInternational Union of CrystallographyInternational Union of Crystallographyhttp://journals.iucr.orgurn:issn:0108-7673Acta Crystallographica Section A: Foundations of Crystallography publishes articles reporting fundamental advances in all areas of crystallography in the broadest sense. This includes metacrystals such as photonic or phononic crystals, i.e. structures on the meso- or macroscale that can be studied with crystallographic methods. The central themes are, on the one hand, experimental and theoretical studies of the properties and arrangements of atoms, ions and molecules in condensed matter, periodic, quasiperiodic or amorphous, ideal or real, and, on the other, the theoretical and experimental aspects of the various methods to determine these properties and arrangements. In the case of metacrystals, the focus is on the methods for their creation and on the structure-property relationships for their interaction with classical waves.text/htmlActa Crystallographica Section A Foundations and Advancestextdaily12002-01-01T00:00+00:00med@iucr.orgActa Crystallographica Section A Foundations and AdvancesCopyright (c) 2014 International Union of Crystallographyurn:issn:0108-7673Forthcoming article in Acta Crystallographica Section A Foundations and Advanceshttp://journals.iucr.org/logos/rss10a.gif
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Still imageHigh-symmetry embeddings of interpenetrating periodic nets. Essential rings and patterns of catenation
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Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Bonneau and O'Keeffedoi:10.1107/S2053273314019950International Union of CrystallographyenPERIODIC NETS; INTERPENETRATING NETS; CATENATION; POLYCATENATIONtext/htmlHigh-symmetry embeddings of interpenetrating periodic nets. Essential rings and patterns of catenationtextUnconstrained and X-ray constrained extremely localized molecular orbitals: analysis of the reconstructed electron density
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Experimentally constrained wavefunctions are calculated for α-glycylglycine using high-resolution X-ray structure factors and the extremely localized molecular orbital formalism.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Leonardo H. R. Dos Santos et al.doi:10.1107/S2053273314019652International Union of CrystallographyExperimentally constrained wavefunctions are calculated for α-glycylglycine using high-resolution X-ray structure factors and the extremely localized molecular orbital formalism.enX-RAY CONSTRAINED WAVEFUNCTION; EXTREMELY LOCALIZED MOLECULAR ORBITAL; HIGH-RESOLUTION X-RAY DIFFRACTION; GLYCYLGLYCINEExperimentally constrained wavefunctions are calculated for α-glycylglycine using high-resolution X-ray structure factors and the extremely localized molecular orbital formalism.text/htmlUnconstrained and X-ray constrained extremely localized molecular orbitals: analysis of the reconstructed electron densitytextAnalysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge method
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This report describes complete practical guidelines and insights for the crystalline sponge method, which have been derived through the first use of synchrotron radiation on these systems, and includes a procedure for faster synthesis of the sponges. These guidelines will be applicable to crystal sponge data collected at synchrotrons or in-house facilities, and will allow researchers to obtain reliable high-quality data and construct chemically and physically sensible models for guest structural determination.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Timothy R. Ramadhar et al.doi:10.1107/S2053273314019573International Union of CrystallographyThis report describes complete practical guidelines and insights for the crystalline sponge method, which have been derived through the first use of synchrotron radiation on these systems, and includes a procedure for faster synthesis of the sponges. These guidelines will be applicable to crystal sponge data collected at synchrotrons or in-house facilities, and will allow researchers to obtain reliable high-quality data and construct chemically and physically sensible models for guest structural determination.enX-RAY CRYSTALLOGRAPHY; CRYSTALLINE SPONGE METHOD; METAL-ORGANIC FRAMEWORK; SINGLE-CRYSTAL-TO-SINGLE-CRYSTAL TRANSFORMATION; SYNCHROTRON RADIATIONThis report describes complete practical guidelines and insights for the crystalline sponge method, which have been derived through the first use of synchrotron radiation on these systems, and includes a procedure for faster synthesis of the sponges. These guidelines will be applicable to crystal sponge data collected at synchrotrons or in-house facilities, and will allow researchers to obtain reliable high-quality data and construct chemically and physically sensible models for guest structural determination.text/htmlAnalysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge methodtextAtomic scale study of polar Lomer–Cottrell and Hirth lock dislocation cores in CdTe
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Using atomic-column-resolution high-angle annular dark-field imaging and X-ray spectrum imaging in an aberration-corrected scanning transmission electron microscope, dislocation core structures in zinc-blende CdTe are examined. The formation mechanisms of the polar core structures is described using Thompson's tetrahedron adapted to reactions of polar dislocations as they appear in CdTe and other zinc-blende solids.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Tadas Paulauskas et al.doi:10.1107/S2053273314019639International Union of CrystallographyUsing atomic-column-resolution high-angle annular dark-field imaging and X-ray spectrum imaging in an aberration-corrected scanning transmission electron microscope, dislocation core structures in zinc-blende CdTe are examined. The formation mechanisms of the polar core structures is described using Thompson's tetrahedron adapted to reactions of polar dislocations as they appear in CdTe and other zinc-blende solids.enLOMER-COTTRELL DISLOCATIONS; HIRTH LOCK DISLOCATIONS; STAIR-ROD DISLOCATIONS; DISLOCATION CORES; HAADF; STEM; XEDS; CDTEUsing atomic-column-resolution high-angle annular dark-field imaging and X-ray spectrum imaging in an aberration-corrected scanning transmission electron microscope, dislocation core structures in zinc-blende CdTe are examined. The formation mechanisms of the polar core structures is described using Thompson's tetrahedron adapted to reactions of polar dislocations as they appear in CdTe and other zinc-blende solids.text/htmlAtomic scale study of polar Lomer–Cottrell and Hirth lock dislocation cores in CdTetextFrom direct-space discrepancy functions to crystallographic least squares
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Crystallographic least-squares properties are derived from discrepancy functions working in direct space.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Carmelo Giacovazzodoi:10.1107/S2053273314019056International Union of CrystallographyCrystallographic least-squares properties are derived from discrepancy functions working in direct space.enLEAST SQUARES; SCALING FACTORS; UNLOCATED MODELS; VECTOR REFINEMENTCrystallographic least-squares properties are derived from discrepancy functions working in direct space.text/htmlFrom direct-space discrepancy functions to crystallographic least squarestextPrediction of molecular crystal structures by a crystallographic QM/MM model with full space-group symmetry
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A new crystallographic quantum-mechanical/molecular-mechanical model for the prediction of molecular crystal structures is described. Applications include polymorphic systems and molecules from the CCDC blind tests of crystal structure prediction.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Mörschel and Schmidtdoi:10.1107/S2053273314018907International Union of CrystallographyA new crystallographic quantum-mechanical/molecular-mechanical model for the prediction of molecular crystal structures is described. Applications include polymorphic systems and molecules from the CCDC blind tests of crystal structure prediction.enCRYSTAL STRUCTURE PREDICTION; QUANTUM MECHANICS/MOLECULAR MECHANICS; DENSITY FUNCTIONAL THEORY; BLIND TESTA new crystallographic quantum-mechanical/molecular-mechanical model for the prediction of molecular crystal structures is described. Applications include polymorphic systems and molecules from the CCDC blind tests of crystal structure prediction.text/htmlPrediction of molecular crystal structures by a crystallographic QM/MM model with full space-group symmetrytextIcosahedral symmetry breaking: C60 to C78, C96 and to related nanotubes
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The structure of a particular type of hollow cage fullerenes (C60+N18) is described in detail, and their existence explained from a symmetry-breaking mechanism starting from the perfect icosahedral symmetry of C60 to specific subgroups A2. This mechanism expands previous results describing the existence of other groups of fullerenes (C60+N10) based on the breaking of the icosahedral symmetry of C60 to the subgroup H2. The mechanism is extended to describe the cases that generate carbon nanotubes, as well as stereoisomers of the C78 molecule.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Mark Bodner et al.doi:10.1107/S2053273314017215International Union of CrystallographyThe structure of a particular type of hollow cage fullerenes (C60+N18) is described in detail, and their existence explained from a symmetry-breaking mechanism starting from the perfect icosahedral symmetry of C60 to specific subgroups A2. This mechanism expands previous results describing the existence of other groups of fullerenes (C60+N10) based on the breaking of the icosahedral symmetry of C60 to the subgroup H2. The mechanism is extended to describe the cases that generate carbon nanotubes, as well as stereoisomers of the C78 molecule.enFINITE COXETER GROUP; SYMMETRY BREAKING; FULLERENES; NANOTUBESThe structure of a particular type of hollow cage fullerenes (C60+N18) is described in detail, and their existence explained from a symmetry-breaking mechanism starting from the perfect icosahedral symmetry of C60 to specific subgroups A2. This mechanism expands previous results describing the existence of other groups of fullerenes (C60+N10) based on the breaking of the icosahedral symmetry of C60 to the subgroup H2. The mechanism is extended to describe the cases that generate carbon nanotubes, as well as stereoisomers of the C78 molecule.text/htmlIcosahedral symmetry breaking: C60 to C78, C96 and to related nanotubestextAn alternative method for data analysis in serial femtosecond crystallography
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A new diffraction data analysis method for serial femtosecond crystallography is proposed. This method is found to obtain satisfactory results.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Zhang, Li and Wudoi:10.1107/S2053273314016982International Union of CrystallographyA new diffraction data analysis method for serial femtosecond crystallography is proposed. This method is found to obtain satisfactory results.enSERIAL FEMTOSECOND CRYSTALLOGRAPHY; SFX; FREE-ELECTRON LASERS; STRUCTURE ANALYSISA new diffraction data analysis method for serial femtosecond crystallography is proposed. This method is found to obtain satisfactory results.text/htmlAn alternative method for data analysis in serial femtosecond crystallographytextDensity functional calculations of polysynthetic Brazil twinning in α-quartz. Corrigenda and addenda
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Two corrections and a number of additions are made to the article by Grimmer & Delley [Acta Cryst. (2012), A68, 359–365].Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Grimmer and Delleydoi:10.1107/S2053273314016842International Union of CrystallographyTwo corrections and a number of additions are made to the article by Grimmer & Delley [Acta Cryst. (2012), A68, 359–365].en[ALPHA]-QUARTZ; TWINNING; DENSITY FUNCTIONAL CALCULATIONSTwo corrections and a number of additions are made to the article by Grimmer & Delley [Acta Cryst. (2012), A68, 359–365].text/htmlDensity functional calculations of polysynthetic Brazil twinning in α-quartz. Corrigenda and addendatextThe coincidence problem for shifted lattices and crystallographic point packings
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The coincidence problem for lattices, shifted lattices and crystallographic point packings is considered. The results are illustrated using a shifted square lattice and the diamond packing.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Loquias and Zeinerdoi:10.1107/S2053273314016696International Union of CrystallographyThe coincidence problem for lattices, shifted lattices and crystallographic point packings is considered. The results are illustrated using a shifted square lattice and the diamond packing.enCOINCIDENCE SITE LATTICE; GRAIN BOUNDARIES; CRYSTALLOGRAPHIC POINT PACKING; MULTILATTICES; DIAMOND LATTICEThe coincidence problem for lattices, shifted lattices and crystallographic point packings is considered. The results are illustrated using a shifted square lattice and the diamond packing.text/htmlThe coincidence problem for shifted lattices and crystallographic point packingstextAn accurate parameterization for scattering factors, electron densities and electrostatic potentials for neutral atoms that obey all physical constraints
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An efficient procedure and computer program have been developed to perform an accurate parameterization for scattering factors with the correct inclusion of all physical constraints.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Lobato and Van Dyckdoi:10.1107/S205327331401643XInternational Union of CrystallographyAn efficient procedure and computer program have been developed to perform an accurate parameterization for scattering factors with the correct inclusion of all physical constraints.enPARAMETERIZATION; ELECTRON SCATTERING FACTORS; X-RAY SCATTERING FACTORS; ATOMIC POTENTIAL; ELECTRON DENSITYAn efficient procedure and computer program have been developed to perform an accurate parameterization for scattering factors with the correct inclusion of all physical constraints.text/htmlAn accurate parameterization for scattering factors, electron densities and electrostatic potentials for neutral atoms that obey all physical constraintstextUse of bond-valence sums in modelling the diffuse scattering from PZN (PbZn1/3Nb2/3O3)
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Diffuse scattering from PZN (PbZn1/3Nb2/3O3) has been analysed by combining the average structure revealed by Bragg diffraction with the requirements of the bond-valence sum. This goes beyond previous models, which are more prescriptive and artificial in nature, although not all key aspects of the short-range order can be shown to arise `naturally' out of the modelled interactions.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733R. E. Whitfield et al.doi:10.1107/S2053273314016143International Union of CrystallographyDiffuse scattering from PZN (PbZn1/3Nb2/3O3) has been analysed by combining the average structure revealed by Bragg diffraction with the requirements of the bond-valence sum. This goes beyond previous models, which are more prescriptive and artificial in nature, although not all key aspects of the short-range order can be shown to arise `naturally' out of the modelled interactions.enNEUTRON SCATTERING; X-RAY SCATTERING; RELAXOR FERROELECTRICS; SINGLE CRYSTALS; SHORT-RANGE ORDER; DIFFUSE SCATTERING; PZNDiffuse scattering from PZN (PbZn1/3Nb2/3O3) has been analysed by combining the average structure revealed by Bragg diffraction with the requirements of the bond-valence sum. This goes beyond previous models, which are more prescriptive and artificial in nature, although not all key aspects of the short-range order can be shown to arise `naturally' out of the modelled interactions.text/htmlUse of bond-valence sums in modelling the diffuse scattering from PZN (PbZn1/3Nb2/3O3)textTwelvefold symmetric quasicrystallography from the lattices F4, B6 and E6
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Twelvefold symmetric quasicrystallographic structures are obtained from the projections of the lattices described by the Coxeter–Weyl groups W(F4), W(B6) and W(E6). The strip-projection technique leads to results compatible with some experimental data.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Koca, Koca and Kocdoi:10.1107/S2053273314015812International Union of CrystallographyTwelvefold symmetric quasicrystallographic structures are obtained from the projections of the lattices described by the Coxeter–Weyl groups W(F4), W(B6) and W(E6). The strip-projection technique leads to results compatible with some experimental data.enLATTICES; COXETER-WEYL GROUPS; STRIP PROJECTION; CUT-AND-PROJECT TECHNIQUE; QUASICRYSTALLOGRAPHYTwelvefold symmetric quasicrystallographic structures are obtained from the projections of the lattices described by the Coxeter–Weyl groups W(F4), W(B6) and W(E6). The strip-projection technique leads to results compatible with some experimental data.text/htmlTwelvefold symmetric quasicrystallography from the lattices F4, B6 and E6textFinite noncrystallographic groups, 11-vertex equi-edged triangulated clusters and polymorphic transformations in metals
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The one-to-one correspondence between a set of cosets of the Mathieu group M11, block sets of the Steiner system S(4, 5, 11) and 11-vertex equi-edged triangulated clusters determines symmetry-allowable transformations between different 11-vertex triangulated clusters as automorphisms of the Steiner system S(4, 5, 11). The transformations can describe local reconstructions corresponding to polymorphic transformations in metals.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Talis and Kraposhindoi:10.1107/S2053273314015733International Union of CrystallographyThe one-to-one correspondence between a set of cosets of the Mathieu group M11, block sets of the Steiner system S(4, 5, 11) and 11-vertex equi-edged triangulated clusters determines symmetry-allowable transformations between different 11-vertex triangulated clusters as automorphisms of the Steiner system S(4, 5, 11). The transformations can describe local reconstructions corresponding to polymorphic transformations in metals.enSYMMETRY GROUPS; COMBINATORY ANALYSIS; POLYMORPHIC TRANSFORMATIONS; ATOMIC CLUSTERSThe one-to-one correspondence between a set of cosets of the Mathieu group M11, block sets of the Steiner system S(4, 5, 11) and 11-vertex equi-edged triangulated clusters determines symmetry-allowable transformations between different 11-vertex triangulated clusters as automorphisms of the Steiner system S(4, 5, 11). The transformations can describe local reconstructions corresponding to polymorphic transformations in metals.text/htmlFinite noncrystallographic groups, 11-vertex equi-edged triangulated clusters and polymorphic transformations in metalstextAccurate atomic displacement parameters from time-of-flight neutron-diffraction data at TOPAZ
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Accurate atomic displacement parameters obtained from time-of-flight single-crystal diffraction neutron data, collected at the newly commissioned SNS beamline TOPAZ, are presented for two organic crystals and compared to those obtained from four alternative methods: experimental charge-density modelling, high-order independent-atom models, estimates from combined TLS analysis and literature values as implemented in SHADE, and Hirshfeld atom refinement based on X-ray diffraction data.Copyright (c) 2014 International Union of Crystallographyurn:issn:2053-2733Mads R. V. Jørgensen et al.doi:10.1107/S2053273314015599International Union of CrystallographyAccurate atomic displacement parameters obtained from time-of-flight single-crystal diffraction neutron data, collected at the newly commissioned SNS beamline TOPAZ, are presented for two organic crystals and compared to those obtained from four alternative methods: experimental charge-density modelling, high-order independent-atom models, estimates from combined TLS analysis and literature values as implemented in SHADE, and Hirshfeld atom refinement based on X-ray diffraction data.enHYDROGEN-ATOM MODELLING; ANISOTROPIC DISPLACEMENT PARAMETERS; NEUTRON DIFFRACTION; X-RAY STRUCTURE REFINEMENT; ELECTRON-DENSITY REFINEMENTAccurate atomic displacement parameters obtained from time-of-flight single-crystal diffraction neutron data, collected at the newly commissioned SNS beamline TOPAZ, are presented for two organic crystals and compared to those obtained from four alternative methods: experimental charge-density modelling, high-order independent-atom models, estimates from combined TLS analysis and literature values as implemented in SHADE, and Hirshfeld atom refinement based on X-ray diffraction data.text/htmlAccurate atomic displacement parameters from time-of-flight neutron-diffraction data at TOPAZtext