InO6 Octahedra Research Articles

Indium strontium hydrogen phosphate SrIn2[PO3(OH)]4: Synthesis and crystal structure

Indium strontium hydrogen nitrate SrIn2[PO3(OH)]4 was synthesized under mild hydrothermal conditions (T = 180 or 200°C) and characterized using IR spectroscopy, chemical analysis, and thermal analysis. A structure model obtained ab initio was refined by the Rietveld method: a= 9.6412(1) A, b = 13.763(1) A, c = 9.3579(1) A, Robs = 0.0183, Rp = 0.0493 (space group B2212, Z = 4). The acentricity of the structure was confirmed by SHG tests (I2ω/I2ω(SiO2) ≈ 2.0). In the SrIn2[PO3(OH)]4 structure, indium atoms reside in distorted InO6 octahedra and form, together with PO3(OH) tetrahedra, a mixed 3D structure {In2[PO3(OH)]4}3∞2− whose voids are occupied by Sr2+ cations (CN = 8). The block-dimer In2(HPO4)10 is the most informative unit of the framework. Blocks are condensed into infinite columns running in the [101] direction. The compound is thermally stable up to 400°C.

Indium Doping in Barium Cerate: the Relation between Local Symmetry and the Formation and Mobility of Protonic Defects

The solid solution series Ba(In,Ce)O3-δ has been investigated with respect to structure, formation, and mobility of protonic defects. Compared to the limited solubility of Y2O3 in BaCeO3 and BaZrO3, the complete solubility of In2O3 is suggested to reflect a relation between absolute hardness of the dopant and the ease of insertion into the hosting lattices. Extended X-ray absorption fine structure (EXAFS) was used to probe the local environment of In3+ in barium cerate: in the surroundings of the dopant, the orthorhombic structure is strongly modified, resulting in an increase of local symmetry. The InO6 octahedra are very regular, and there is no indication for any defect clustering. This is suggested to be the main reason for the low entropy of formation of protonic defects by water dissolution. The mobility of such defects is slightly lower than in Y-doped BaCeO3, but at high dopant levels the high local symmetry allows for formation of very high concentrations of protonic defects. This leads to high ...

New Series of Indium Formates: Hydrothermal Synthesis, Structure and Coordination Modes

Three new indium(III) compounds, In(HCOO)3 (1), In2(HCOO)5(OH) (2), and In(HCOO)2(OH) (3), were synthesized under hydrothermal conditions and characterized by single crystal and powder X-ray diffraction experiments, as well as by IR spectroscopy, elemental analysis, and coupled TG-DSC-MS measurement. All of these compounds adopt 3D framework structures consisting of InO6 octahedra and the 2.11 binding modes of formate with the (syn, syn-; syn, anti-; anti, anti-) configurations. The structural investigation of these indium formates reveals that the gradual introduction of the hydroxyl groups into the structures induces the polymerization of the InO6 octahedra, that is, InO6 is isolated in 1, becomes dimeric in 2, and finally forms 1D chains in 3. In addition, a simple formula that may be used for estimating the overall coordination number of the formate in Ma(HCOO)bLc is proposed.

Photocatalytic properties of MIn(WO4)2(M = Li, Na, and K)

MIn(WO4)2(M = Li, Na, and K) with InO6and WO6octahedra were synthesized via a conventional solid-state reaction method. The photophysical and photocatalytic properties were studied. Compared with WO3, which is unable to evolve H2from an aqueous CH3OH solution under illumination, the three materials can evolve H2and O2from aqueous solutions with CH3OH and AgNO3sacrificial reagents, respectively. The activity order of photocatalytic H2evolution is NaIn(WO4)2> LiIn(WO4)2> KIn(WO4)2under irradiation (λ > 200 nm). Under irradiation (λ > 300 nm), however, LiIn(WO4)2has a high activity for photocatalytic H2evolution over NaIn(WO4)2. It is also noteworthy that LiIn(WO4)2and NaIn(WO4)2exhibit the ability to split pure water. The results suggest that the bottoms of the conduction bands in these photocatalysts are raised to meet the potential requirements of photocatalytic H2evolution.

Rb6(InCo)2(Si9O26): A Mixed‐Metal Silicate Containing 20‐Membered‐Ring Silicate Single Layers with a Very Low Si:O Ratio.

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Rb6(InCo)2(Si9O26): A Mixed-Metal Silicate Containing 20-Membered-Ring Silicate Single Layers with a Very Low Si:O Ratio

A new cobalt-indium silicate, Rb6(InCo)2(Si9O26), has been synthesized via a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction. It crystallizes in the noncentrosymmetric orthorhombic space group Aba2 (No. 41) with a = 20.779(1) A, b = 12.0944(6) A, c = 10.7761(5) A, V =2708.1(2) A(3), and Z = 4. The structure consists of 20-membered-ring silicate single layers of corner-sharing SiO4 tetrahedra interconnected by dimers of edge-sharing CoO4 tetrahedra and InO6 octahedra into a 3D framework. The Si:O ratio for the title compound is the lowest among the known single-layer silicates. Magnetic susceptibility confirms the divalent state of the cobalt ion. The powder sample has a second-harmonic-generation signal, confirming the absence of a center of symmetry in the structure.

Octahedral—Tetrahedral Framework Structures of InAsO4×H2O and PbIn(AsO4)(AsO3OH).

AbstractFor Abstract see ChemInform Abstract in Full Text.

Photocatalytic Activity of the RuO2-Dispersed Composite p-Block Metal Oxide LiInGeO4 with d10−d10 Configuration for Water Decomposition

The ruthenium oxide-loaded composite p-block metal oxide LiInGeO4 with d10-d10 configuration exhibited high photocatalytic activity for the overall splitting of water to produce H2 and O2 under UV irradiation. Changes in the photocatalytic activity with the calcination temperature of LiInGeO4, the amount of RuO2 loaded, and the states of RuO2 indicated that the combination of highly crystallized LiInGeO4 and a high dispersion of RuO2 particles resulted in high photocatalytic activity. Structurally, LiInGeO4 contained heavily distorted InO6 octahedra and GeO4 tetrahedra, generating a dipole moment inside. The high photocatalytic performance of RuO2-loaded LiInGeO4 supports the existing view that the photocatalytic activity correlates with the dipole moment. The DFT calculation showed that the top of the valence band (HOMO) was composed of the O 2p orbital while the bottom of the conduction band (LUMO) was formed by the hybridized In 5s5p + Ge 4s4p + O 2p orbitals. The highly dispersed conduction band, indicative of a high mobility of photoexcited electrons, was responsible for the high photocatalytic performance.

In(OH)BDC·0.75BDCH2 (BDC = Benzenedicarboxylate), a Hybrid Inorganic−Organic Vernier Structure

The compound In(OH)BDC.0.75BDCH2 (BDC = benzenedicarboxylate), 1, has been synthesized and characterized by single-crystal X-ray diffraction. The structure comprises two distinct sublattices formed by a covalently linked In(OH)BDC lattice and ordered chains of hydrogen-bonded H2BDC molecules and can be described as a hybrid inorganic coordination polymer-organic vernier structure. Each InO6 octahedron of the octahedral chain has a length of 3.6 A along the chain axis, whereas each H2BDC molecule has a length of 9.6 A along the guest column axis. Therefore, a unit of eight InO6 octahedra of the octahedral chain is just in registry with three H2BDC molecules of the guest column giving a repeat unit of 28.76 A along the channel axis direction.

Octahedral–tetrahedral framework structures of InAsO4·H2O and PbIn(AsO4)(AsO3OH)

Indium arsenate(V) monohydrate, InAsO4.H2O, (I), crystallizes in the structure type of MnMoO4.H2O. The structure is built of In2O8(H2O)2 dimers (mean In-O=2.150 A) corner-linked to slightly distorted AsO4 tetrahedra (mean As-O=1.686 A). The linkage results in a three-dimensional framework, with small voids into which the apical water ligand of the InO5(H2O) octahedron points. The hydrogen bonds in (I) are of medium strength. Lead(II) indium arsenate(V) hydrogen arsenate(V), PbIn(AsO4)(AsO3OH), (II), represents the first reported lead indium arsenate. It is characterized by a framework structure of InO6 octahedra corner-linked to AsO4 and AsO3OH tetrahedra. The resulting voids are occupied by Pb2O10(OH)2 dimers built of two edge-sharing highly distorted PbO6(OH) polyhedra (mean Pb-O=2.623 A). The compound is isotypic with PbFe(III)(AsO4)(AsO3OH). The average In-O bond length in (II) is 2.157 A. In both arsenates, all atoms are in general positions.

Structural characterization and photocatalytic behavior of β-KInW2O8

A photocatalyst KInW2O8 (β phase) with InO6 octahedra was synthesized and its physical and photophysical properties were characterized by XRD, BET measurement, UV-visible diffuse reflectance, respectively. For the first time, the photocatalytic H2 and O2 evolution on this material were investigated in detail. The results showed that O2 could be evolved at an initial rate of 2.1 μmol/g per h under visible light irradiation. Furthermore, H2 could be obtained at an average rate of 1.21 μmol/g per h and O2 at an initial rate of 4.26 μmol/g per h under full arc irradiation. Based on these results, the band structure of the photocatalyst was suggested, indicating that the introduction of indium changed the electronic structure of the W-based oxide.

Crystal structure determination of In3(H3O)(H2PO4)6(HPO4)2 · 4H2O from X-ray powder diffraction

Abstract The crystal structure of indium hydrogen phosphate hydrate, In3(H3O)(H2PO4)6(HPO4)2 · 4H2O, has been determined from X-ray powder diffraction data by using direct methods (EXPO program), and refined by FULLPROF package to R Bragg value of 5.6%. The structure is monoclinic, space group C2/c (No. 15), unit cell dimensions a = 17.0835(5), b = 9.6795(3), c = 17.8776(4) Å, β = 90.301(2)°, V = 2956.2(1) Å3, Z = 4, Dx = 2.73 g/cm3. Hydrogen atoms were placed on calculated positions. There are two unique indium atoms in the crystal structure. InO6 octahedra are connected together via the corners of PO4 tetrahedra to form layers parallel to the xy plane. The layers are linked together by water molecules, located in the interlayer space, through their hydrogen bonds. Within the layers there are hollows occupied by oxonium cations. The compound was found to be isostructural with salts of the composition M III 3MI(H2PO4)6(HPO4)2 · 4H2O, where M III-trivalent metal, M I-monovalent metal, oxonium or ammonium.

Hydrothermal Synthesis, Crystal Structure, Solid‐State NMR Spectroscopy, and Ionic Conductivity of Na5InSi4O12, a Silicate Containing a Single 12‐Membered Ring.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Subsolidus phase relations and crystal structures of the mixed-oxide phases in the In2O3–WO3 system

Subsolidus phase relationships in the In2O3–WO3 system at 800–1400°C were investigated using X-ray diffraction. Two binary-oxide phases—In6WO12 and In2(WO4)3—were found to be stable over the range 800–1200°C. Heating the binary-oxide phases above 1200°C resulted in the preferential volatilization of WO3. Rietveld refinement was performed on three structures using X-ray diffraction data from nominally phase-pure In6WO12 at room temperature and from nominally phase-pure In2(WO4)3 at 225°C and 310°C. The indium-rich phase, In6WO12, is rhombohedral, space group R3̄ (rhombohedral), with Z=1, a=6.22390(4) Å, α=99.0338(2)° [hexagonal axes: aH=9.48298(6) Å, c=8.94276(6) Å, aH/c=0.9430(9)]. In6WO12 can be viewed as an anion-deficient fluorite structure in which 1/7 of the fluorite anion sites are vacant. Indium tungstate, In2(WO4)3, undergoes a monoclinic–orthorhombic transition around 250°C. The high-temperature polymorph is orthorhombic, space group Pnca, with a=9.7126(5) Å, b=13.3824(7) Å, c=9.6141(5) Å, and Z=4. The low-temperature polymorph is monoclinic, space group P21/a, with a=16.406(2) Å, b=9.9663(1) Å, c=19.099(2) Å, β=125.411(2)°, and Z=8. The structures of the two In2(WO4)3 polymorphs are similar, consisting of a network of corner sharing InO6 octahedra and WO4 tetrahedra.

Hydrothermal synthesis and characterization of new hybrid open-framework indium phosphate-oxalates

Three new hybrid open-framework indium phosphate-oxalates, I, Na[InPO4(C2O4)0.5] · H2O II, [C2N2-H10]0.5[InPO4(C2O4)0.5] III, [C3N2H12]0.5[In2(PO4)(HPO4)(C2-O4)] · H2O have been hydrothermally synthesized by using organic amines such as ethylamine, 1,3-diaminopropane and alkali metal ions such as Na+ as structure-directing agents (SDA). The structures of these compounds were characterized by single crystal X-ray diffraction. The structure of I consists of InO6 octahedra that are linked by phosphate and oxalate groups to generate a three-dimensional framework with intersecting 8-membered ring (MR) channels parallel to the [100] and [010] directions. The structure of II is similar to that of I except that its guest species are protonated ethylamines. III is built from indiumphosphate double-six-rings second building units linked by oxalate units, resulting in large circular 16 MR channels. Single crystal X-ray diffraction measurements show that the SDA of I — III are located in their channels. Crystal data for these three indium phosphate-oxalates are as follows: I, triclinic, space group:P-1 (No. 2),a = 5.5662(17)A,b = 6.454(2)A,c = 8.966(3)A,α= 102.609(4)°,β = 107.319(3)°,γ = 94.426(4)°,V= 296.56(16)A3,Z = 2,M = 294.81,Φ calcu = 3.301 g/cm3,R1 = 0.0275,wR2 = 0.0731. II, triclinic, space group:P-1 (No. 2),a = 5.653(4)A,b = 6.627(4)A,c = 9.391(8)A,α = 70.788(8)°,β = 75.836(12)°,γ = 89.681(9)°,V = 321.1(4)A3,Z = 2,M = 283.85,ρ calcu = 2.936 g/cm3,R1= 0.0664,wR2 = 0.1572. III, orthorhombic, space group:Pccm (No. 49),a = 10.350(2) A,b = 12.190(2)A,c = 13.000(3)A,V = 1640.2(6)A3,Z = 4,M =272.32,ρ calcu = 2.206 g/cm3,R1=0.0691,wR2 = 0.1831.

Hydrothermal Synthesis, Crystal Structure, Solid-State NMR Spectroscopy, and Ionic Conductivity of Na5InSi4O12, a Silicate Containing a Single 12-Membered Ring

Na5InSi4O12 has been synthesized by a high-temperature, high-pressure hydrothermal method and characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. It is isotypic to Na5ScSi4O12. The structure consists of 12-membered single rings of corner-sharing SiO4 tetrahedra linked together via corner sharing by single InO6 octahedra to form a 3-D framework that delimits two types of channels along the c-axis. There are six independent sodium sites. The Na atoms within the 12-ring channels are immobile and the Na atoms within 7-ring channels are highly mobile. The 29Si MAS NMR exhibits one Q3 and one Q4 resonance, each of which is split into two peaks because of inequivalent chemical environments caused by partially occupied Na sites in the 7-ring channels. Na ion conductivity measurements on a pressed pellet of the title compound were performed. The Arrhenius plot of dc conductivity shows a change in slope near 220 °C. We attribute this to the activation of the Na site that is situated ...

Photocatalytic Activity for Water Decomposition of Indates with Octahedrally Coordinated d10 Configuration. II. Roles of Geometric and Electronic Structures

The effects of electronic and local structures on the photocatalytic activities for water decomposition of different kinds of indates [MIn2O4 (M = Ca, Sr), Sr0.93Ba0.07In2O4, and AInO2 (A = Li, Na)] were studied. Raman spectroscopic measurements were performed to characterize their structures. The geometric structures of InO6 octahedral units were compared among the indates, and it was shown that the photocatalytically active indates possessed distorted InO6 octahedra with dipole moment, and there was a correlation between the photocatalytic activities and the dipole moment. A plane-wave density function theory (DFT) was applied to calculate the density of state and band energy diagram for SrIn2O4. The valence band was composed of the O 2p orbital, whereas the conduction band consisted of the hybridized In 5s5p orbitals with large dispersion, indicative of large mobility of photoexcited electrons in the conduction band. The electronic feature of SrIn2O4 was compared with that of a representative transition metal oxide of BaTi4O9 with an octahedrally coordinated d0 metal ion. On the basis of the electronic and geometric consideration, a mechanism is proposed: internal fields due to the dipole moment promote the charge separation, while the broad sp conduction bands with large dispersion permit photoexcited electrons to move to RuO2 particles dispersed as a promoter.

Crystal structure of dilithium indium (monophosphate-monohydrogenmonophosphate), Li2In[(PO4)(HPO4)

HInLi2O8P2, monoclinic, P121/n1 (No. 14), a = 4.8345(7) A, b = 8.236(1) A, c = 7.728(1) A, = 103.466(7)°, V = 299.2 A, Z = 2, Rgt(F) = 0.022, wRref(F) = 0.060, T = 295 K. Source of material Li2In[(PO4)(HPO4)] was obtained during borophosphate synthesis under mild hydrothermal conditions. The reaction was carried out with a mixture of In (0.574 g, dissolved in 3 ml 37% HCl), LiH2PO4 (10.393 g), and Li2B4O7 (1.691 g) with the molar ratio of 1 : 20 : 2. The mixture was filled in a 20 ml teflon autoclave with a filling degree of about 50%. Autoclaves were placed in an oven with subsequent heating at 443 K for 7 days. All starting materials were of analytical grade and used without further purification. The composition of the product was confirmed by chemical analysis (ICP) with Li : In : P : O : H = 1.96 : 0.93 : 2 : 7.5 : 1.3. Experimental details The hydrogen position could not be located from difference Fourier analysis, maybe because of affection of the heavy atom indium. Therefore, the position of the hydrogen atom in the isotypic compound Li2Fe[(PO4)(HPO4)] [3] was assumed for the title compound and maintained constant in the refinement. Discussion Only two lithium indium phosphates (LiInP2O7, Li3In2(PO4)3) [1,2] have been reported up to now. Here we report on the first acid lithium indium phosphate containing a HPO4-group. The crystal structure of the title compound is characterized by isolated InO6 octahedra which share common O-atoms with adjacent PO4 tetrahedra to form a three-dimensional network structure. Each PO4 tetrahedron shares common O-corners with three neighboring InO6 octahedra. As mentioned above, by analogy to the isotypic phase Li2Fe[(PO4)(HPO4)], the H atom was assumed to be disordered and in an ordered model O3PO···H–OPO3 groups would exist. The crystal structure contains eight-membered rings formed by alternating InO6 octahedra (4×) and phosphate tetrahedra (4×). Lithium cations are located within channels formed by the eight-membered rings running along the a axis. Within the channels, each eight-membered ring is divided by the O···H–O bridges. In—O bond distances in the InO6-octahedron range from 2.129 A to 2.147 A. Each Li atom is coordinated by 4 oxygen atoms with bond distances d(Li—O) = 1.951 A – 2.047 A. Bond lengths and angles of the phosphate tetrahedra are reflecting those in other phosphates [1,2]. Z. Kristallogr. NCS 217 (2002)307-308 307 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: colorless isometric fragment of 0.10 mm diameter Wavelength: Mo K radiation (0.71073 A) : 44.88 cm−1 Diffractometer, scan mode: Rigaku AFC7-CCD, 400 images, = 0.6° scan, = 0.6°, 2 max: 59.78° N(hkl)measured, N(hkl)unique: 4423, 732 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 694 N(param)refined: 62 Programs: SIR92 [4], SHELXL-97 [5], DIAMOND [6] Table 1. Data collection and handling. H(1) 4e 0.50 0.571 0.519 0.518 0.05 Table 2. Atomic coordinates and displacement parameters (in A). Atom Site Occ. x y z Uiso

Crystal structure of ammonium indium di(hydrogenmonophosphate), (NH4)In[PO3(OH)

H6InNO8P2, monoclinic, P121/c1 (No. 14), a = 9.6004(4) A, b = 8.2820(4) A, c = 9.6693(3) A, = 116.205(4)°, V = 689.8 A 3 , Z =4 ,Rgt(F) = 0.040, wRref(F 2 ) = 0.104, T = 295 K. Source of material (NH4)In[P2O6(OH)2] was synthesized under mild hydrothermal conditions. The reactions were carried out with mixtures of InCl3, LiCl·H2O, NaBO2·4H2O and (NH4)H2PO4 with the molar ratio of 1:4:9:6 in aqueous solution. The mixture was sealed in 20 ml glass tube. The pH value of the solution was about 0.2. The filling of the solution were about 30% of the glass tubes. The glass tubes were placed in an oven with subsequent heating at 413 K for 7 days. The starting materials are all of analytical grade and used without further purification. Discussion There was only one ammonium-indium phosphate [1] and one ammonium-indium borophospahte [2] reported up to now and the title compound is another indium phosphate with ammonium cation obtained as a by-product of new borophosphate, NaIn[BP2O8(OH)] [3]. The title compound has a new structure type which is characterized by isolated InO6 octahedra sharing common O-corners with six isolated PO3(OH) tetrahedra to form a three-dimensional network structure. Every PO3(OH) tetrahedron shares common O-corners with three InO6 octahedra besides the terminal OH group. In the structure, there are eight-membered rings formed by four InO6 octahedra and four hydrogenphosphate tetrahedra. Ammonium groups are distributed within the open elliptical channels running along the a axis. In InO6 octahedron the In—O bond distances range from 2.107 A to 2.168 A. Bond lengths and angles of hydrogenphosphate PO3(OH) tetrahedra are similar to other phosphates.

Crystal structure of diammonium indium (monophosphate-monohydrogenmonophosphate), (NH4)2ln[(PO4)(HPO4)

H9InN2O8P2, orthorhombic, Fdd2 (No. 43), a = 17.459(4) A, b = 9.200(2) A, c = 9.720(2) A, V = 1561.3 A, Z = 8, Rgt(F) = 0.061, wRref(F) = 0.148, T = 295 K. Source of material (NH4)2In[(PO4)(HPO4)] was synthesized under mild hydrothermal conditions. The reactions were carried out with mixtures of InCl3, H3BO3 and (NH4)H2PO4 with the molar ratio of 1:6 : 8 in aqueous solution. The mixture was sealed in 20 ml glass tubes. The filling of the solution were about 30% of the glass tubes. The glass tubes were placed in an oven with subsequent heating at 413 K for 7 days. All starting materials were of analytical grade and used without further purification. Discussion There were only two ammonium-indium phosphates [1,2] and one ammonium-indium borophospahte [3] reported up to now and the title compound is another indium phosphate with ammonium cation. The title compound has a new structure type which is characterized by isolated InO6 octahedra sharing common O-corners with six isolated PO4 tetrahedra to form a three dimensional network structure. Each PO4 tetrahedron shares common O-corners with three InO6 octahedra. According to the present model, the hydrogen atom bridges symmetrically two PO4 tetrahedra. However, the H atom is presumably disordered, splitting in two positions, and in an ordered model the O3PO···H–OPO3 groups would exist. The structure can also be considered as a packing of layers perpendicular to the a-axis. Each layer is constructed by fusing eight-membered rings formed by four InO6 octahedra and four phosphate (or hydrogenphosphate) tetrahedra. The alternating layers are shifted by 1/4 of a period along both band c-axis with respect to their neighboring layers. This construction results to two sets of channels runing along the [011] and [011] directions. The channels have a nearly rectangular cross section and are formed by two five-membered U-shaped half-rings in an up-and-down fashion. The ammonium groups are distributed within the channels. The In—O bond distances within the InO6 octahedron range from 2.093 A to 2.171 A. Bond lengths and angles in the phosphate PO4 tetrahedra are similar to those in other phosphates. Z. Kristallogr. NCS 217 (2002)309-310 309 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: colorless prism, size 0.07 × 0.07 × 0.10 mm Wavelength: Mo K radiation (0.71073 A) : 34.61 cm−1 Diffractometer, scan mode: Enraf Nonius CAD4, /2 2 max: 67.74° N(hkl)measured, N(hkl)unique: 834, 834 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 644 N(param)refined: 57 Programs: SIR92 [4], SHELXL-97 [5], DIAMOND [6] Table 1. Data collection and handling. O(1) 16b 0.2476(7) 0.423(1) 0.496(1) 0.013(2) O(2) 16b 0.2476(7) 0.594(1) 0.689(1) 0.009(2) O(3) 16b 0.1205(5) 0.518(1) 0.583(1) 0.013(2) O(4) 16b 0.1962(6) 0.340(1) 0.726(1) 0.015(2) N(1) 16b 0.1439(9) 0.824(2) 0.499(2) 0.024(3) H(1) 8a 1/4 1/4 0.7135 0.05 H(2) 16b 0.1879 0.8895 0.5567 0.05 H(3) 16b 0.1486 0.8201 0.4136 0.05 H(4) 16b 0.0885 0.8504 0.5257 0.05 H(5) 16b 0.1694 0.7424 0.5515 0.05 Table 2. Atomic coordinates and displacement parameters (in A). Atom Site x y z Uiso