... that it crystallizes as a structural variant of the putative (AlV 4+,5+ 14 O 40 ) n − vanadoaluminate complex, [AlV 4+ V 5+ 12 O 39 ] 11− . That variant is derived through the random removal of one of the two apical vanadate octahedra, elucidating the cause of difficulties in the refinement of the preliminary...

... coordination and B 5+ cations occurring in more regular octahedral coordination ( Hurlbut 1957 , Skapski & Rogers 1965 , Galliski et al . 2001 , Zubkova et al . 2002 ). Therefore, with regard to the low distortion of both A O 6 and B O 6 octahedra and the mismatch between bond-valence sums...

... group Cmc 2 1 with unit-cell parameters a = 16.2392(2), b = 10.96370(10), c = 15.3367(2) Å, V = 2730.57(5) Å 3 , and Z = 4. Its crystal structure is characterized by clusters of six-membered rings of edge-sharing AlO 6 octahedra with an SiO 3 (OH) tetrahedron situated at the center of each ring...

... ). The primitive unit cell of gibbsite contains two sheets of Al octahedra. Half of the hydroxyls on the dioctahedral sheet lie parallel to the sheet, and the rest stand normal to the sheet because one-third of the cation sites within the gibbsite sheet are vacant ( Fig. 1a ). In contrast to gibbsite, Mg(OH) 2...

...Javier Cuadros; Joseph R. Michalski; M. Darby Dyar Abstract The model of Fe 3+ distribution between octahedra and tetrahedra in dioctahedral smectites by Decarreau and Petit (2014) used data from infrared analysis. From their own and other general evidence, the resulting data are likely...

... COLLECTION AND FINAL UNIT CELL PARAMETERS (Å) FOR SERANDITE–SCHIZOLITE–PECTOLITE CRYSTALS DETERMINED IN THIS STUDY 2021 serandite–schizolite–pectolite series order-disorder equilibrium polyhedral distortion Kirchhoff network equations structural strain ribbon of edge-sharing octahedra...

...Aaron J. Lussier; Frank C. Hawthorne ABSTRACT Infinite chains of edge-sharing octahedra occur as fundamental building blocks (FBBs) in the structures of several hundred mineral species. Such chains consist of a backbone of octahedra to which decorating polyhedra may be attached. The general...

... structure with several different cation/anion sites and the large number of chemical substitutions possible at these sites ( e.g ., Hawthorne & Oberti 2007 ). The main structural unit is an I-beam consisting of a strip of M (1), M (2), and M (3) octahedra (containing C-group cations, Fig. 1...

...-dimensional kagomé networks in minerals where the kagomé node atoms are octahedrally coordinated in hexagonal tungsten bronze (HTB) arrays. Octahedral tilting, coupled with capping of the apical anions of the triangular groupings of octahedra in the HTB layers, gives rise to several important mineral groups...

... of the structure of Si-rich Mg-sursassite determined in this study projected onto the (010) plane. Blue = isolated SiO 4 and Si 2 O 7 sorosilicate groups, pink = M 4 and M 5 octahedra (Al), green = M 3 octahedron (50%Al, 50%Si), orange spheres = M 1 (Mg) and M 2 (Mg). Rows of M (2,3,4,5) octahedra and VII...

... of both minerals comprise heteropolyhedral slabs of composition [ XM 1 Fe 2 3 + (OH) 2 (PO 4 ) 4 ], that are linked together via corner-sharing of PO 4 tetrahedra with isolated [ M 2(O p ) 2 (H 2 O) 4 ] octahedra. The structures differ in the mode of linkage of the M 2 octahedra, which is via trans O p...

... of kenngottite was solved using single-crystal X-ray diffraction data and refined to wR obs = 0.088 for 350 reflections with I > 2σ( I ). The structure contains trimeric clusters of face-shared octahedra (Mn–Fe–Mn) that are connected into chains along [001] by sharing edges with Mn-centred octahedra...

... that of the latter (11.86 Å 3 ); the T O 4 tetrahedra in the blue diopside (<λ tet > =1.006; σ θ(tet) 2 = 24.37–24.69) are less distorted than that of the green diopside (<λ tet > = 1.007; σ θ(tet) 2 = 27.94); the M 1O 6 octahedra in the former (<λ oct > =1.006; σ θ(oct) 2 = 20.39–21.13) are more...

... 0.12 Zn 0.02 ) Σ3.08 (As 3.95 P 0.07 ) Σ4.02 O 16 , and the idealised formula is Na 2 KAl 3 (AsO 4 ) 4 . Ozerovaite is orthorhombic: Cmca , a = 10.615(2), b = 20.937(3), c = 6.393(1) Å, V = 1420.9(3) Å 3 , Z = 4. The crystal structure ( R 1 = 0.031) is constructed of AlO 6 octahedra and AsO 4...

...+ O 4 (OH) 2 and Te 6+ O 4 (OH) 2 octahedra. The chains link to one another via shared octahedral corners to form [Cu 2+ Te 6+ O 4 (OH) 2 ] 2– sheets. Interlayer Mg(H 2 O) 6 octahedra link the sheets via hydrogen bonds. §   Corresponding author e-mail address : akampf@nhm.org 9 May...

... kröhnkite-type chains can be identified. These sheets are arranged in an …ABAB… stacking sequence. A different understanding of the crystal structure can be obtained when the tetrahedra and octahedra are used for the construction of a mixed tetrahedral-octahedral or heteropolyhedral framework ( Fig...

... d elements were analysed. We establish that the incorporation of Me 3+ cations is controlled by the ratio between the sizes of Y O 6 and Z O 6 octahedra and does not exceed eight atoms per formula unit (apfu), while the incorporation of Me 2+ cations is controlled by the charge balance and does...

.... Its crystal structure was solved from single-crystal XRD data ( R = 0.0358). The TiO 6 octahedra are interconnected via O vertices to form infinite (Ti–O) ∝ chains. The remaining vertices of each TiO 6 octahedron are shared with SO 4 tetrahedra thus forming one-dimensional [TiO(SO 4 ) 2 ] units...