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Structure Type (structure + type)
Kinds of Structure Type Selected AbstractsAn Analysis of Tenure and House Structure Type by Household CompositionFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 2 2007Stephanie E. Vanderford This study examined the relation of household composition and characteristics with each of two variables, tenure status and structural type of residence. Past research related to tenure status has considered household composition and characteristics in a limited manner, and very little empirical work has addressed the relations of those variables with house structure type. The three structure types assessed were manufactured housing, multifamily site-built homes, and single-family site-built homes. The authors extended past research by considering more complicated household compositions and also identified the importance of knowing more complete information about all the residents of a home to understand both tenure and house structure type. Family composition and the presence of extended family members, an unmarried partner, and other unrelated individuals all explained di ferences in tenure and house structure type. The findings suggest the significance of family and household characteristics when understanding variations in tenure and house structure type. [source] ,-Y2[Si2O7]: A New Structure Type with the Yttrialite Series.CHEMINFORM, Issue 50 2006Ingo Hartenbach Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Ag2Te2O7, a Novel Silver Tellurate of Weberite Structure Type.CHEMINFORM, Issue 39 2006Wilhelm Klein Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] BaSm5[Si9Al3N20]O , A Nitridoaluminosilicate Oxide with a New Structure Type Composed of "Star-Shaped" [N[4]((Si,Al)N3)4] Units as Secondary Building Units.CHEMINFORM, Issue 20 2006Alexandra Lieb Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] New Tetragonal Structure Type for A2Ca10Sb9 (A: Li, Mg).CHEMINFORM, Issue 13 2006Electronic Variability Around a Zintl Phase. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Bi7-xAs1+xMo3O21 (0 , x , 1) a New Pillar Structure Type: Synthesis, Crystal Structure and Conductivity.CHEMINFORM, Issue 44 2004F. Duc Abstract For Abstract see ChemInform Abstract in Full Text. [source] R6TT,2, New Variants of the Fe2P Structure Type.CHEMINFORM, Issue 15 2004Lu6MoSb, Sc6TTe2 (T: Ru, the anti-Typic Sc6Te0.80Bi1.68. Abstract For Abstract see ChemInform Abstract in Full Text. [source] Ce2Ir5B2, A New Structure Type of Ternary Borides.CHEMINFORM, Issue 48 2003P. Salamakha Abstract For Abstract see ChemInform Abstract in Full Text. [source] CsMn2P2, a Manganese(II, III) Phosphide with BaZn2P2 Structure, With a Contribution to the BaAl4 Structure Type.CHEMINFORM, Issue 6 2003H. G. von Schnering Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: New Heteropolyanions of the M2X2W20 Structure Type with Antimony(III) as a Heteroatom.CHEMINFORM, Issue 34 2002M. Piepenbrink Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Ternary Lanthanoid Ruthenium Gallides with a High Gallium Content: Ln2Ru3Ga10 (Ln: Yb, Lu) with a New Structure Type and LnRu2Ga8 (Ln: La,Nd) with CaCo2Al8 -Type Structure.CHEMINFORM, Issue 5 2002Martin Schlueter Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Investigation of Bimetallic Thiocyanates Belonging to ABTC Structure Type: ZnCd(SCN)4 and AHg(SCN)4 (A: Zn, Cd, Mn) as Nonlinear Optical Crystal Materials.CHEMINFORM, Issue 22 2001X.-Q. Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Three Structure Types for Strontium Copper(I) Lanthanide(III) Selenides SrCuLnSe3 (Ln: La, Gd, Lu).CHEMINFORM, Issue 37 2006Sabine Strobel Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] An Analysis of Tenure and House Structure Type by Household CompositionFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 2 2007Stephanie E. Vanderford This study examined the relation of household composition and characteristics with each of two variables, tenure status and structural type of residence. Past research related to tenure status has considered household composition and characteristics in a limited manner, and very little empirical work has addressed the relations of those variables with house structure type. The three structure types assessed were manufactured housing, multifamily site-built homes, and single-family site-built homes. The authors extended past research by considering more complicated household compositions and also identified the importance of knowing more complete information about all the residents of a home to understand both tenure and house structure type. Family composition and the presence of extended family members, an unmarried partner, and other unrelated individuals all explained di ferences in tenure and house structure type. The findings suggest the significance of family and household characteristics when understanding variations in tenure and house structure type. [source] Diagrammatic Separation of Different Crystal Structures of A2BX4 Compounds Without Energy Minimization: A Pseudopotential Orbital Radii ApproachADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Xiuwen Zhang Abstract The A2BX4 family of compounds manifest a wide range of physical properties, including transparent conductivity, ferromagnetism, and superconductivity. A 98% successful diagrammatic separation of the 44 different crystal structures of 688 oxide A2BX4 compounds (96% for 266 oxide-only) is described by plotting the total radius of the A atom RA versus the radius of the B atom RB for many A2BX4 compounds of known structure types and seeking heuristically simple, straight boundaries in the RA versus RB plane that best separate the domains of different structure types. The radii are sums RA,=,Rs(A),+,Rp(A) of the quantum-mechanically calculated "orbital radii" Rs(Rp), rather than empirical radii or phenomenological electronegativity scales. These success rates using first-principles orbital radii uniformly exceed the success rates using classic radii. Such maps afford a quick guess of the crystal structure of a yet unmade A2BX4 compound by placing its atomic orbital radii on such maps and reading off its structure type. [source] Semiconducting half-Heusler and LiGaGe structure type compoundsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2009Frederick Casper Abstract Compounds with LiAlSi (half-Heusler) and LiGaGe structure types have been investigated by means of band structure calculations. The LiAlSi structure type is known as the half-Heusler structure type, whereas LiGaGe is a closely related hexagonal variant. A remarkable feature of some XYZ half-Heusler compounds with 8 and 18 valence electrons is, that despite being composed of only metallic elements, they are semiconductors. More than 100 semiconducting compounds within these structure types are known. LiGaGe compounds have an additional degree of freedom, namely the degree of puckering of the layers. These compounds can become semiconducting at a certain degree of puckering. Half-metallic behavior is rarely found in this structure type. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] CVD growth of carbon nanotubes using molecular nanoclusters as catalystPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11-12 2009K. Goss Abstract The growth of isolated carbon nanotubes (CNTs) using chemical vapour deposition process catalysed by the molecular nanocluster {Mo72Fe30} of the Keplerate structure type in different oxidation states is studied on different substrates. The molecule in its oxidized state (MoVI/FeIII) agglomerates in solution. Thus, nucleation from large catalyst particles cannot provide a narrow CNT diameter distribution. However, a partially reduced and charged form of the same molecule (MoV/MoVI) enables growth from small nucleation sites as evidenced by atomic force microscope imaging, albeit the yield in this case is dramatically reduced. [source] On symmetry classes of crystal structuresACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2009Hans Burzlaff An open-ended classification scheme for crystal structures based on Wyckoff sets and affine normalizer groups is proposed. It is free of metrical and geometrical considerations. All structures of one structure type belong to the same symmetry class. An application is given for the Inorganic Crystal Structure Database (version 2, 2007). [source] Towards a generalized vision of oxides: disclosing the role of cations and anions in determining unit-cell dimensionsACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2010Ángel Vegas Theoretical calculations of the electron-localization function show that, at the volumes of the two CaO phases (rocksalt and CsCl type), the parent Ca structures (fcc: face-centred cubic and sc: simple cubic, respectively) exhibit charge concentration zones which coincide with the positions occupied by the O atoms in their oxides. Similar features, also observed for the pairs Ca/CaF2 and BaSn/BaSnO3, are supported by recent high-pressure experiments as well as electron-localization function (ELF) calculations, carried out on elemental K. At very high pressures, the elemental K adopts the hP4 structure, topologically identical to that of the K atoms in high-pressure K2S and high-temperature ,-K2SO4. Moreover, the ELF for the hP4 structure shows charge concentration (,,2 electrons) at the sites occupied by the S atoms in the high-pressure K2S phase. All these features confirm the oxidation/high-pressure equivalence as well as the prediction of how cation arrays should be metastable phases of the parent metals. For the first time to our knowledge, the structure type, dimension and topology of several oxides and fluorides (CaO, CaF2 and BaSnO3) are explained in univocal physical terms. [source] Structure of caesium disulfate at 120 and 273,KACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009Kenny Ståhl The crystal structures of Cs2S2O7 at 120 and 273,K have been determined from X-ray single-crystal data. Caesium disulfate represents a new structure type with a uniquely high number of independent formula units at 120,K: In one part caesium ions form a tube surrounding the disulfate ions, [Cs8(S2O7)6+]n; in the other part a disulfate double-sheet sandwiches a zigzagging caesium ion chain, [Cs2(S2O7)6,]n. Caesium disulfate shows an isostructural order,disorder transition between 230 and 250,K, where two disulfate groups become partially disordered above 250,K. The Cs+ -ion arrangement shows a remarkable similarity to the high-pressure RbIV metal structure. [source] Trigonal structures of ABe2BO3F2 (A = Rb, Cs, Tl) crystalsACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2009Colin D. McMillen Several interesting fluoroberyllium borates were synthesized hydrothermally and characterized by single-crystal X-ray diffraction. The crystal structures of RbBe2BO3F2 (RBBF; rubidium fluoroberyllium borate) and CsBe2BO3F2 (CBBF; caesium fluoroberyllium borate), previously determined in the space group C2, were reinvestigated for higher symmetry and found to have more suitable solutions in the space group R32. TlBe2BO3F2 (TBBF; thallium fluoroberyllium borate) was synthesized as a novel compound also having this trigonal structure type. Details of the space-group determination and unique structural features are discussed. These crystal structures were compared with that of KBe2BO3F2, revealing interesting structural trends within this family of compounds that are also discussed. A crystallographic explanation of the physical morphology is postulated. [source] Isosymmetrical phase transition in ,-YbV4O8ACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2008Karen Friese The structure of YbV4O8 is related to the CaFe2O4 structure type. VO6 octahedra form a three-dimensional framework with tunnels in which the Yb3+ ions are incorporated. Two different polymorphs , and , are known and differ mainly in the arrangement of the Yb ions within the framework. We studied the structure and magnetic properties of ,-YbV4O8 as a function of temperature. At approximately 70,K ,-YbV4O8 undergoes a first-order isosymmetrical phase transition (P21/n,P21/n). While in the high-temperature , phase the three V3+ and one V4+ are disordered over the four symmetrically independent octahedral sites, in the low-temperature ,, phase complete charge ordering is observed. The transition is accompanied by a paramagnetic,paramagnetic anomaly in the magnetic susceptibility data which can be interpreted on the basis of spin-gap formation. The transition mechanism in the , polymorph is very similar to that observed earlier in the , polymorph at 185,K. [source] Cluster approach to the Ti2Ni structure typeACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2006D. Rodi It has been established that the 16(c) first coordination clusters in the Ti2Ni structure type (space group Fd3m) follow icosahedral-face orientational ordering along regular tetrahedron edge directions. The actual crystal structure appears due to the prevalence of the face-centred cubic translational ordering over the cluster assembling. This way, the competition of the `regular' crystal phase and its icosahedral analogue is reconstructed at the atomic level. The model accounts for the markedly different electronic characteristics at the different crystallographic positions obtained by hyperfine interaction measurements, and other curious experimental facts help to create an exact physical definition of the first coordination in the solid state and to distinguish between various structure types on fundamental principles. [source] Two-dimensionally modulated structure of the rare-earth polysulfide GdS2,x (x = 0.18 , 13/72)ACTA CRYSTALLOGRAPHICA SECTION B, Issue 6 2003Rafael Tamazyan The crystal structure of GdS2,x is determined by single-crystal X-ray diffraction as a 144-fold superstructure of the ZrSSi structure type. The superstructure is described as a two-dimensional, commensurately modulated structure with the superspace group P4/n(,,½)(00)(ss) and with , = 1/4 and , = 1/3. Structure refinements within the classical approach, employing the 144-fold supercell, fail because most of the superlattice reflections have zero intensities within the experimental resolution. Within the superspace approach the absent superlattice reflections are systematically classified as higher-order satellite reflections. Accordingly, the superspace approach has been used to refine the structure model comprising the basic structure positions and the amplitudes of the modulation functions of the three crystallographically independent atoms. The quality of fit to the diffraction data and the values of the refined parameters are independent of the assumption on the true symmetry (incommensurate or a 12,×,12,×,2, I -centred superlattice with different symmetries). Arguments of structural plausibility then suggest that the true structure is a superstructure with space group I, corresponding to sections of superspace given by (t1, t2) equal to [(4n, 1)/48, (4m, 3)/48] or [(4n, 3)/48, (4m, 1)/48] (n and m are integers). Analysis of the structure, employing both superspace techniques (t plots) and the supercell structure model all show that the superstructure corresponds to an ordering of vacancies and an orientational ordering of S dimers within the square layers of the S2 atoms. [source] Twinning and intergrowth of rare earth boride carbidesACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2002Oliver Oeckler Twins and intergrown crystals of tetragonal rare earth boride carbides, especially those with the La5B2C6 structure type, have been investigated by high-resolution electron microscopy and X-ray diffraction. The structure of the twin interface has been determined. It provides an explanation for coherently intergrown domains of different structure. The Sc3C4 structure type is remarkable because it is frequently intergrown with La5B2C6 -type phases. It provides, for instance, a model for the intergrowth of other types, e.g. Gd4B3C4 and Gd5B2C5. The presence of metal-atom square nets in different orientations in the structures accounts for a number of intergrowth phenomena. The possibilities and limitations of X-ray structure determinations are discussed with respect to actual examples. [source] Redetermination of iron dialuminide, FeAl2ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010Ihor Chumak The crystal structure of iron dialuminide [Corby & Black (1973). Acta Cryst. B29, 2669,2677] has been redetermined on a single crystal synthesized from the elements by arc melting. The compound crystallizes in the triclinic space group P with 19 atoms per unit cell, one Fe site being on an inversion centre. The crystal structure can be described as an inclusion-plus-deformation derivative of the orthorhombic YPd2Si structure type. [source] K2ScSn(AsO4)3: an arsenate-containing langbeiniteACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010William T. A. Harrison The title compound, dipotassium tri-,-arsenato-scandium(III)tin(IV), is the first arsenate-containing langbeinite to be characterized by single-crystal methods and crystallizes in the aristotype P213 cubic symmetry for this structure type in which the K+ ions and the octahedral scandium and tin cations lie on crystallographic threefold axes. The ScIII and SnIV ions show a slight segregation over the two octahedral sites, with Sc/Sn populations of 0.582,(5):0.418,(5) on one site and 0.418,(5):0.582,(5) on the other. Bond-valence-sum calculations indicate that the K+ ions are significantly underbonded in this structure and the O atoms show large anisotropic displacement parameters, as also seen in other langbeinites. The crystal studied was found to be a merohedral twin with a 0.690,(16):0.310,(16) domain ratio. [source] Low-dimensional hydrogen-bonded structures in the 1:1 and 1:2 proton-transfer compounds of 4,5-dichlorophthalic acid with the aliphatic Lewis bases triethylamine, diethylamine, n -butylamine and piperidineACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Graham Smith The structures of the proton-transfer compounds of 4,5-dichlorophthalic acid (DCPA) with the aliphatic Lewis bases triethylamine, diethylamine, n -butylamine and piperidine, namely triethylaminium 2-carboxy-4,5-dichlorobenzoate, C6H16N+·C8H3Cl2O4,, (I), diethylaminium 2-carboxy-4,5-dichlorobenzoate, C4H12N+·C8H3Cl2O4,, (II), bis(butanaminium) 4,5-dichlorobenzene-1,2-dicarboxylate monohydrate, 2C4H12N+·C8H2Cl2O42,·H2O, (III), and bis(piperidinium) 4,5-dichlorobenzene-1,2-dicarboxylate monohydrate, 2C5H12N+·C8H2Cl2O42,·H2O, (IV), have been determined at 200,K. All compounds have hydrogen-bonding associations, giving discrete cation,anion units in (I) and linear chains in (II), while (III) and (IV) both have two-dimensional structures. In (I), a discrete cation,anion unit is formed through an asymmetric R12(4),N+,H...O2 hydrogen-bonding association, whereas in (II), chains are formed through linear N,H...O associations involving both aminium H-atom donors. In compounds (III) and (IV), the primary N,H...O-linked cation,anion units are extended into a two-dimensional sheet structure via amide,carboxyl N,H...O and amide,carbonyl N,H...O interactions. In the 1:1 salts (I) and (II), the hydrogen 4,5-dichlorophthalate anions are essentially planar with short intramolecular carboxyl,carboxyl O,H...O hydrogen bonds [O...O = 2.4223,(14) and 2.388,(2),Å, respectively]. This work provides a further example of the uncommon zero-dimensional hydrogen-bonded DCPA,Lewis base salt and the one-dimensional chain structure type, while even with the hydrate structures of the 1:2 salts with the primary and secondary amines, the low dimensionality generally associated with 1:1 DCPA salts is also found. [source] Al14Ba8La26.3Ru18Sr53.7O167: a variant of cubic perovskite with isolated RuO6 unitsACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010F. J. Zúñiga The crystal structure of the title aluminium barium lanthanum ruthenium strontium oxide has been solved and refined using neutron powder diffraction to establish the parameters of the oxygen sublattice and then single-crystal X-ray diffraction data for the final refinement. The structure is a cubic modification of the perovskite ABO3 structure type. The refined composition is Ba0.167La0.548Sr1.118Ru0.377Al0.290O3.480, and with respect to the basic perovskite structure type it might be written as (Ba8La13.68Sr34.32)(Al13.92La12.64Ru18.08Sr19.36)O192,x, with x = 24.96. The metal atoms lie on special positions. The A -type sites are occupied by Ba, La and Sr. The Ba atoms are located in a regular cuboctahedral environment, whereas the La and Sr atoms share the same positions with an irregular coordination of O atoms. The B -type sites are divided between two different Wyckoff positions occupied by Ru/Al and La/Sr. Only Al and Ru occupy sites close to the ideal perovskite positions, while La and Sr move away from these positions toward the (111) planes with high Al content. The structure contains isolated RuO6 octahedra, which form tetrahedral substructural units. [source] The new ternary phases of La3(Zn0.874Mg0.126)11 and Ce3(Zn0.863Mg0.137)11ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010Volodymyr Pavlyuk The new ternary intermetallic title compounds, namely trilanthanum undeca(zinc/magnesium), La3(Zn0.874Mg0.126)11, (I), and tricerium undeca(zinc/magnesium), Ce3(Zn0.863Mg0.137)11, (II), are isostructural and crystallize in the orthorhombic La3Al11 structure type. These three phases belong to the same structural family, the representative members of which may be derived from the tetragonal BaAl4 structure type by a combination of internal deformation and multiple substitution. Compared to the structure of La3Al11, in (I), a significant decrease of 11.9% in the unit-cell b axis and an increase in the other two directions, of 3.6% along a and 5.2% along c, are observed. Such an atypical deformation is caused by the closer packing of atoms in the unit cell due to atom shifts that reflect strengthening of metallic-type bonding. This structural change is also manifested in a significant difference in the coordination around the smaller atoms at the 8l Wyckoff position (site symmetry m). The Al atom in La3Al11 is in a tricapped trigonal prismatic environment (coordination number 9), while the Zn atoms in (I) and (II) are situated in a tetragonal antiprism with two added atoms (coordination number 10). [source] | |||||||||||||||||||