4e Sites Research Articles

Crystal structure and magnetic properties of melt spun Sm(Co,V)7 ribbons

The crystal structure and magnetic properties of melt spun Sm(Co,V)7 ribbons have been investigated. It was found that SmCo7−xVx ribbons may crystallize in pure TbCu7-type structure for x=0.1–0.3 spun at a high wheel speed of 40 m/s. The structure refinement results show that the doping element V prefers to occupy the 2e site of TbCu7-type structure. Besides, transmission electron microscopy images show that with increasing V content, the grain size was refined from 200–400 nm for x=0.1 to 40–100 nm for x=0.3. As a result, the intrinsic coercivity enhances effectively from 1.9 kOe for SmCo7 ribbon to 11.5 kOe for SmCo6.7V0.3 ribbon. It is also verified that a slight addition of C to SmCo7−xVx could further refine the microstructure, resulting in the improvement of the magnetic properties of SmCo7−xVx ribbons. The optimal magnetic properties of σr=58.7 emu/g, Hic=13.5 kOe, and (BH)max=9.3 MG Oe can be obtained for SmCo6.9V0.1C0.1 ribbon.

Diffusion of Li atoms in LiMn2O4 - A structural point of view -

The structure of LiMn2O4, its phase transition at around 290 K, and the diffusion mechanism of Li are discussed based on the recent synchrotron X-ray diffraction and molecular dynamics simulation studies. The high-temperature modification (cubic Fd 3m) is essentially of spinel-type containing various types of disorder; (1) the Li atoms are not located exactly at the tetrahedral 8a sites, but mainly distributed among four positions 0.14 A apart from 8a, (2) some portion of Li atoms are further displaced toward the 16c octahedral interstices with a notable accumulation at the positions 0.35 A apart from 16c, and (3) the O atoms also show a statistical distribution around their ideal 32e sites. The low-temperature modification adopts a 3 × 3 × 1 superstructure (orthorhombic Fddd) with respect to the high-temperature modification. The bond-length fluctuation has been observed along the pseudo-tetragonal Jahn-Teller distortion direction parallel to the a axis in the heterocubane Mn24O94 cluster. The four Mn2 atoms in the heterocubane presumably shares three electrons in the e-parentage low-energy-level orbitals by the double-exchange Zener mechanism. The time-averaged oxidation state for Mn2 is estimated to be +3.25. The heterocubane Zener polarons are isolated with each other and embedded in an ordered way in the charge-ordered matrix containing Mn1III, Mn3III, Mn4IV and Mn5IV. Two kinds of diffusion mechanisms for Li atoms are proposed for the high-temperature modification from the molecular dynamics simulation. One is a microscopic version of the classical picture for diffusion based on the concentration difference in diffusion species. This mechanism requires an activation energy of ca. 0.25 eV to jump over a saddle point at the bottleneck. The other mechanism is a diffusion accompanied by the local lattice distortion coupled with the 3d electron transfer between a pair of nearby Mn atoms. This requires no activation energy for Li to pass through the bottleneck. The valence exchange between +3 and +4 in the neighboring Mn pair prompts the displacement of coordinating O atoms along the pseudo-tetragonal Jahn-Teller distortion direction, which presumably plays a principal role in opening the bottleneck of oxygen triangle along the diffusion pathway.

Martensitic phase transition from cubic to tetragonal V3Si: an electronic structure study

In this study we focus on the subtle changes which occur in the electronic structure and in the Fermi surface topology with the low temperature (21.3 K) cubic → tetragonal martensitic phase transition in V3Si. From the calculations it has been verified the occurrence of a charge transfer from V atoms to Si atoms, with the phase transition to a tetragonal variant of the A-15 structure. The orbital population of s- and p-states of V atoms in the 2e and 4k sites of the tetragonal phase are practically the same. Major differences are seen in the occupation of d-states. There is a decrease in the average electronic energy with the structural transition, which occurs as a result of the emptying of V d-states (mostly from bands 19–20), and these electrons enter preferentially into the Si p-orbitals. The present results thus indicate that the electronic features of the martensitic transition of V3Si, besides being intimately related to the splitting of the Γ12 into the Γ1+ and Γ3+ states and the position of the Γ1+ state relatively to EF, is mainly associated with the gain in the average electronic energy which occurs from an electron transfer from V-d → Si-p states. This is the main source to explain the stability of the tetragonal phase formed at low temperature in this system.

Phase Width and Site Preferences in the EuMgxGa4−x Series

AbstractA series of EuMgxGa4−x compounds were synthesized using high temperature, solid‐state methods and characterized by both powder and single crystal X‐ray diffraction. All compounds crystallize in the tetragonal BaAl4‐type structure (space group I4/mmm, Z = 2, Pearson symbol tI10) with full occupancy of Ga at the apical atom (4e) site and mixed‐occupancy of Mg and Ga at the basal atom (4d) site. Six compositions were analyzed by single crystal X‐ray diffraction: EuMg0.21(1)Ga3.79(1), EuMg0.91(1)Ga3.09(1), EuMg1.22(1)Ga2.78(1), EuMg1.78(1)Ga2.22(1), EuMg1.84(1)Ga2.16(1), and EuMg1.94(1)Ga2.06(1). As the larger Mg atoms increasingly replace Ga atoms at the basal site in EuMgxGa4−x, the a‐axis lengths at first decrease and then increase, while the c‐axis lengths increase monotonically along the series. The phase width of the BaAl4‐type EuMgxGa4−x series is identified to be 0 ≤ x ≤ 1.94(1), a range which corresponds to 12.06(1)‐14 valence electrons per formula unit, and can be understood by their electronic structures using density of states (DOS) curves calculated by tight‐binding calculations. Mg substitution for Ga at the basal site is consistent with the site preferences for mixed metals on the three‐dimensional framework of the BaAl4‐structure based on both electronegativities and sizes, and provides the rationale for the unusual behavior in lattice parameters. The observed site preference was also rationalized by total electronic energies calculated for two different coloring schemes.

The effect of Mo atoms in ternary nitrides with [formula omitted]-type structure

The effect of Mo atoms in ternary η -type nitrides, T 3Mo 3N and T 2Mo 4N (T = Fe, Co, Ni), has been investigated by atomistic simulation. The calculated lattice constants and atomic coordinates are in good agreement with experiments. Calculated results show that adding more Mo atoms makes the crystal energies of T 2Mo 4N decrease markedly, which indicates that Mo atoms can stabilize these nitrides. The Mo atoms prefer to occupy the 16d sites and avoid the 32e sites in T 2Mo 4N. The calculated elastic constants and bulk modulus are compared with the experimental and the density functional theory (DFT) results. Furthermore, in order to evaluate the thermodynamic contribution by Mo atoms, the phonon density of states, specific heat, and vibrational entropy of Fe 3Mo 3N and Fe 2Mo 4N are also investigated.

HoF[SeO3] und Ho3F[SeO3]4: Zwei fluorid‐derivatisierte Oxoselenate(IV) des Holmiums

AbstractHoF[SeO3] and Ho3F[SeO3]4: Two Fluoride‐ Derivatized Holmium Oxoselenates(IV)Three different structure types of rare‐earth metal(III) fluoride oxoselenates(IV) with the formula MF[SeO3] (M = Y, La, Lu) exist so far, whereas for the intermediate lanthanoids M3F[SeO3]4‐type compounds are known with the elements gadolinium and dysprosium. Holmium is now the first lanthanoid realizing both formula types of fluoride oxoselenates(IV), HoF[SeO3] as well as Ho3F[SeO3]4. HoF[SeO3] crystallizes isotypically to YF[SeO3] in the monoclinic system with space group P21/c (a = 657.84(6), b = 688.73(7), c = 718.25(7) pm, β = 99.213(5)° and Z = 4). Ho3+ at the general site 4e is surrounded by six oxide and two fluoride anions forming [HoO6F2]11− polyhedra (d(Ho–O) = 229−244 plus 261 pm, d(Ho–F) = 219 and 221 pm, CN(Ho3+) = 8). Like in YF[SeO3] the $^{2}_{\infty}\rm \{[HoO_{3}F]^{4-}\}$ sheets resulting from condensation of these polyhedra are interconnected by Se4+ cations showing a ψ1‐tetrahedral oxygen coordination as discrete [SeO3]2− anions (d(Se–O) = 167 – 175 pm), but by imaginary removal of the latter only $^{1}_{\infty}\rm \{[HoF^{v}_{2/2}]^{2+}\}$zigzag chains running parallel to the [001] direction remain. Ho3F[SeO3]4 crystallizes in the non‐centrosymmetric hexagonal space group P63mc (a = 1030.24(3), c = 680.37(2) pm and Z = 2). Three [HoO8F]14− polyhedra (d(Ho–O) = 232–254 pm and d(Ho–F) = 233 pm, CN(Ho3+) = 9) at a time are connected via common O2···F edges and four attached ψ1‐tetrahedral [SeO3]2− anions (d(Se–O) = 169–170 pm) to complete the basic building block {FHo3[(Se1)(O1)3][(Se2)(O2)(O3)2]3}. These entities with F−‐centered (Ho3+)3 triangles represent a single formula unit and share triangular (O1,O3,O3) faces with six other blocks in [001] direction. Large hexagonal channels are remaining in between which harbor the “lone‐pair” electrons of the isolated [(Se2)(O2)(O3)2]2− anions. Due to the free position of z/c in space group P63mc, z/c = 1/4 was chosen for the unique fluoride anion on site 2b (site symmetry: 3m.) in order to unify the descriptions for all M3F[SeO3]4‐type compounds eventually. The syntheses of HoF[SeO3] and Ho3F[SeO3]4 succeeded by reacting holmium sesquioxide (Ho2O3), holmium trifluoride (HoF3) and selenium dioxide (SeO2) in molar ratios of 1 : 1 : 3 and 4 : 1 : 12, respectively, with CsBr as fluxing agent within five days at 750 °C in evacuated graphitized fused‐silica ampoules.

Hexagonal TmMn6Sn4Ge2 investigated by neutron diffraction and 119Sn Mössbauer spectroscopy

The hexagonal compound TmMn6Sn4Ge2 has been investigated by neutron diffraction and 119Sn Mössbauer spectroscopy. The location of Ge atoms on the 2(c) site has been confirmed. Above 230 K, an easy plane helimagnetic structure is stable and below 70 K an easy axis ferrimagnetic structure prevails. The magnetic moments at 2 K are μTm = 6.93 μB and μMn = 2.25 μB. In the intermediate temperature range, we observed a tilting of the spiral plane. The intermediate magnetic structure is clearly observed by the 119Sn local probe through a field distribution for the Sn(2e) site and a quadrupolar distribution for the Sn(2d) site. The change of the magnetocrystalline anisotropy of the Tm sublattice with respect to the easy plane observed in the parent stannide TmMn6Sn6 might be related either to a shortening of the Tm–Mn distances or to a deformation of coordination shell around the Tm atom, both being caused by the location of Ge atoms on the 2(c) site. The stabilisation of the ferrimagnetic structure at low temperature might be driven by stronger Tm–Mn interactions that result from the reduced Tm–Mn bond lengths.

Ein neues Selten‐Erd‐Metall(III)‐Fluorid‐Oxoselenat(IV): YF[SeO3

AbstractA New Rare‐Earth Metal(III) Fluoride Oxoselenate(IV): YF[SeO3]Just two representatives of the rare‐earth metal(III) fluoride oxoselenates(IV) with the formula type MF[SeO3] (M = La and Lu) exist so far, whereas for the intermediate lanthanoids only M3F[SeO3]4‐type compounds (M = Gd and Dy) were accessible. Because of the similar radius of Y3+ to the radii of the heavier lanthanoid cations, a missing link within the MF[SeO3] series could be synthesized now with the example of yttrium(III) fluoride oxoselenate(IV). Contrary to LuF[SeO3] with its triclinic structure, YF[SeO3] crystallizes monoclinically in space group P21/c (no. 14, a = 657.65(7), b = 689.71(7), c = 717.28(7) pm, β = 99.036(5)° and Z = 4). A single Y3+ cation occupying the general site 4e is surrounded by six oxide and two fluoride anions forming [YO6F2]11− polyhedra (d(Y–O) = 228–243 plus 263 pm, d(Y–F) = 219–220 pm). These are linked via common O···O edges to $^{1}_{\infty}\rm \{[YO^{e}_{4/2}O^{t}_{2/1}F^{t}_{2/1}]^{7-}\}$ chains running along [010] and adjacent chains get tied to each other by sharing common O3···O3 and O3···F edges which results in $^{2}_{\infty}\rm \{[Y(O3)_{3/3}(O2)_{2/2}(O1)_{1/1}F_{2/2}]^{4-}\}$ sheets parallel to (100). The Se4+ cations connect these $^{2}_{\infty}\rm \{[YO_{3}F]^{4-}\}$ sheets as ψ1‐tetrahedral [SeO3]2− anions (d(Se–O) = 168–174 pm) for charge balance via all oxygen atoms. Despite the different coordination numbers of seven and eight for the rare‐earth metal(III) cations the structures of LuF[SeO3] and YF[SeO3] appear quite similar. The $^{1}_{\infty}\rm \{[LUO^{e}_{4/2}O^{t}_{1/1}F^{t}_{2/1}]^{5-}\}$ chains containing pentagonal bipyramids [LuO5F2]9− are connected to $^{2}_{\infty}\rm \{[LUO^{e}_{4/2}O^{t}_{1/1}F^{e}_{2/2}]^{4-}\}$ layers running parallel to the (100) plane again. In fact it is only necessary to shorten the partial structure of the straight $^{1}_{\infty}\rm \{[LUF_{2/2}]^{2+}\}$ chains along [001] to achieve the angular $^{1}_{\infty}\rm \{[YF_{2/2}]^{2+}\}$ chains in YF[SeO3]. As a result of this shortening one oxide anion at a time moves into the coordination sphere of a neighboring Y3+ cation and therefore adds up the coordination number for Y3+ to eight. For the synthesis of YF[SeO3] yttrium sesquioxide (Y2O3), yttrium trifluoride (YF3) and selenium dioxide (SeO2) in a molar ratio of 1 : 1 : 3 with CsBr as fluxing agent were reacted within five days at 750 °C in evacuated graphitized silica ampoules.

Hyperfine interactions on iron in R2−xFe14+2xSi3 (R=Ce, Nd, Gd, Dy, Ho, Er, Lu, Y) compounds studied by Mössbauer spectroscopy

Abstract Compounds R 2− x Fe 14 + 2 x Si 3 with (R = Ce, Nd, Gd, Dy, Ho, Er, Lu, Y) were prepared by the modified Czochralski method and investigated by means of the 57 Fe 14.4 keV Mossbauer spectroscopy and powder X-ray diffraction. The magnetic moment was additionally measured for samples being single crystals. Iron experiencing low magnetic hyperfine field and electric quadrupole interaction was found on (4e) sites in the P 6 3 / mmc structure. Similar iron was found in the R 3 ¯ m structure as well. The non-stoichiometry parameter was determined as being close to 2 x = 0.5 for all compounds investigated. Compound with R = Ho crystallizes in both structures. Our results show that silicon avoids (4f) and (6g) sites for compounds with the P 6 3 / mmc structure (R = Dy, Ho, Er, Lu, Y), whereas it avoids (6c) and (9d) sites for those with R 3 ¯ m structure (R = Nd, Gd, Ho).

Formation of submicron-sized SrFe 12−xAl xO 19 with very high coercivity

Submicron-sized SrFe 12− x Al x O 19 ( x=1.3) was formed in glass-ceramic matrix using controlled thermocrystallization of the SrO–Fe 2O 3–Al 2O 3–B 2O 3 glass and the hexaferrite powder was obtained by removing the matrix phases. The samples were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray (EDX) analysis and magnetization measurements. The glass-ceramic material exhibits very high coercivity value up to 10.18 kOe which approaches a theoretically estimated maximum value for the compound. The hexaferrite powder consists of well faceted single crystals, which adopt the shape of a truncated hexagonal bipyramid. The powder saturation magnetization value is close to the theoretically estimated one for bulk material. Crystal structure of the powder was refined by Rietveld method and distribution of Al atoms on Fe sites was determined. Al atoms occupy 41% of 2a sites, 14% of 12k sites and 5% of 4e(1/2) sites, while 4f sites are not affected.

Hydrogen Bonding and Structure of Ba2Ru2Cl10O×10H2O.

AbstractChemInform 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.

Syntheses and Structures of New Phases AeMxIn4-x (Ae = Sr, Ba; M = Mg, Zn): Size Effects and Site Preferences in BaAl4-Type Structures

The title phases were synthesized via high-temperature solid-state methods and structurally characterized by single-crystal X-ray diffraction. The phase widths of both SrMg(x)In(4-x) (0.85 <or= x <or= 1.53) and BaMg(x)In(4-x) (0 <or= x <or= 1.79) are consistent with size matches between Ae and the encapsulating M-In cages. All compounds crystallize in body-centered tetragonal BaAl(4)-type structure (I4/mmm, Z = 2) except that SrMg(x)In(4-x), 0.85 <or= x <or= 1.24, occurs in the lower-symmetry space group (I4m2, Z = 2) and the atoms are all ordered at the composition SrMgIn(3). The substitution of the effectively smaller Mg or Zn atoms into the indium sublattice of the monoclinic SrIn(4) (C2/m) dramatically changes the structure into the tetragonal BaAl(4)-type structure. Compared with the Mg compounds in which all Mg occupy the basal 4d crystallographic site, Zn occupies the other 4e (apical) site in both BaZn(0.79(2))In(3.21) and SrZn(1.00(4))In(3.00). These differences are related to the interplay of size and electronic factors. The latter may be expressed by not only electronegativities but also total energies according to linear muffin-tin-orbital calculations.

Hydrogen bonding and structure of Ba2Ru2Cl10O·10H2O

Dibarium micro-oxido-bis[pentachloridoruthenate(IV)] decahydrate, Ba(2)Ru(2)Cl(10)O.10H(2)O, has been prepared from ruthenium(III) chloride and barium chloride in hydrochloric acid. It crystallizes in the monoclinic system (space group C2/c). The structure consists of alternating layers of [Ru(2)Cl(10)O](4-) and [Ba(H(2)O)(7)](2+) complex ions along the a direction. The O atom bonded to ruthenium occupies the 4e site, with 1 symmetry, while the other atoms occupy general 8f sites. The overall structure is held together by O-H...O hydrogen bonds and O-H...Cl dipole-dipole interactions.

On the formation of LaFe5Hn

We explore the formation of a LaFe 5 H n hydride by means of density functional theory. Enthalpies of formation Δ H with respect to the elemental metals and H 2 are calculated for various hydrogen configurations in four prototype crystal structures. We find Δ H < 0 in many cases, suggesting the existence of LaFe 5 H n , as does Miedema's semi-empirical model. Δ H is a minimum for the LaFe 5 H 7 stoichiometry with hydrogen occupying the 4e, 8g, and 16m sites in the orthorhombic Cccm structure. Phonon dispersion relations and elastic constants computed for that structure exhibit no anomalies, demonstrating vibrational stability. Similar results for LaFe 5 indicate the possible formation of that compound under pressure.

Rietveld refinement and spectroscopic studies of sodium lead fluoroapatite lacunaire synthesized by hydrothermal method

The structure of NaPb 9(PO 4) 6F(H 2O) 0.33, isostructural with apatite, was determined by X-ray powder diffraction methods and the result of Rietveld refinement is P6 3/ m, a = 9.76396(8) Å and c = 7.27520(9) Å. The final refinement led to R F = 5.4%, R B = 6.6%. In the tunnel, the water molecule (O w) and F − ions appear to be located in 2b and 4e sites, with occupancies of 0.028(6) and 0.075(8), respectively. In the M(1) and M(2) sites the occupancies of Pb and Na are 0.282(3)/0.051(3) and 0.467(5)/0.033(5), respectively. The formula assigned to the compound is [Pb 3.38(4)Na 0.62(4)](1)[Pb 5.60(6)Na 0.40(6)](2)(PO 4) 6F 0.90(10)(H 2O) 0.33(7)□ 0.77(17), where □ = vacancy. The assignment of the observed frequencies in the Raman and infrared spectra is discussed on the basis of a unit-cell group analysis and by comparison with fluor and chloroapatite analogs. The result of 31P and 23Na magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopies confirmed the structural results.

119Sn Mössbauer effect study of UxFe6Sn6 (x=0, 0.2, 0.4, 0.6)

Abstract 119Sn Mossbauer spectroscopy was performed on UxFe6Sn6 (x = 0.2, 0.4, 0.6) crystallizing in a defect isotype of the SmMn6Sn6-type structure. Three different hyperfine fields, Btransf, transferred from the ordered Fe moments are detected on 2e sites at 300 K. These Btransf magnitudes decrease with decreasing number of U nearest neighbours. For x = 0.2 insertion of U atoms only lead to a broadening of the Sn(2c) peaks at 4 K. For x = 0.4 and 0.6 magnetic ordering of the U sublattice seems to induce a slow relaxing Btransf on Sn(2c) and Sn(2d) sites at 4 K. The absence of such an effect in U0.2Fe6Sn6 may suggest that due to its low content in this compound U does not order magnetically down to 4 K.

Magnetic phase transitions and structures of Co 3V 2O 8

Co 3V 2O 8 is a spin- 3/2 system on a Kagomé staircase and is known to undergo two magnetic phase transitions between 6 and 11 K. The H – T phase diagram of Co 3V 2O 8 derived by magnetization measurements on a single crystal is presented. Additionally both ordered magnetic structures were investigated by neutron powder diffraction experiments and solved using Bertaut’s macroscopic theory. For the ferromagnetic phase the magnetic moments of the Co 2+ ions were found to be 1.5 ( 3 ) μ B and 2.7 ( 1 ) μ B at 3.5 K along the crystallographic a axis for the (4a) and (8e) sites, respectively. The antiferromagnetic phase exhibits a magnetic cell with a doubled b axis with respect to the nuclear one. The magnetic moments point along the a axis being 1.8 ( 2 ) μ B (4a) and 1.8 ( 1 ) μ B (8e) at 8 K.

Crystal, electronic and luminescence properties of Eu2+-doped Sr2Al2–xSi1+xO7–xNx

The crystal and electronic structures, as well as the luminescence properties of Sr2Al2–xSi1+xO7–xNx:Eu2+ are reported. First-principles calculations energetically confirm that the Al and Si atoms are in partial ordering in the 2a and 4e sites in Sr2Al2SiO7. In addition, the band structure calculation shows that Sr2Al2SiO7 has an indirect band gap with an energy gap of about 4.07 eV, which is in good agreement with the experimental data (∼5.3 eV) obtained from the diffuse reflection spectrum. The crystal structure of Sr2Al2SiO7 can be modified by Si–N substitution for Al–O in the lattice with a maximum solubility of about x ¼ 0.6. The average bond length of EuSr–(O,N) slightly increases although the lattice parameters decrease with the incorporation of Si–N in Sr2Al2SiO7:Eu2+. Under excitation in the visible spectral region, Sr2Al2–xSi1+xO7–xNx:Eu2+ emits blue to yellow light with a broad emission band in the range of 480–570 nm, varying with both the Eu concentration and the x value. The red shift of the emission band of Eu2+ is associated with an increase in the crystal-field splitting and the covalency, which arise from the incorporation of nitrogen as well as the energy transfer between the Eu ions at high Eu concentrations. Moreover, the Eu ions have a strong effect on both the concentration quenching and the thermal quenching in Sr2Al2–xSi1+xO7–xNx. The temperature dependence of photoluminescence indicates that Sr2Al2–xSi1+xO7–xNx:Eu2+ shows strong thermal quenching due to the dominant nonradiative process at room temperature.

Relationship between Pre-Exponential Factor and Activation Energy of Conductivity in Sintered Ln9.33+x/3Si6-xMxO26 (Ln=La, Nd, Sm, M=Al, Gd) with Apatite-like Structure

Electrical conductivity of a series of Ln9.33+x/3Si6-xMxO26 (Ln=La, Nd and Sm, M=Al and Ga) sinters was examined. The pre-exponential factor and activation energy of the ionic conduction were well related by Meyer-Neldel rule, i.e., G=G00 exp (ΔE/kT0) exp (-ΔE/kT). Most of the sinters were composed with an apatite-like phase in major and sub-products such as LnSiO5 and Ln2O3 in minor proportions. The single phases with apatite-like structure were obtained for the composition of x=1.5. At this composition, the activation energy increased with a decrease in the ionic radius of Ln. The lowest activation energy and highest pre-exponential factor were observed for the combination of Ln=La and M=Al. This result was interpreted by considering the formation of the 4e sites for oxygen with under occupancy and oxygen ion interstitials surrounded with six 6h(La) sites.

Mg2Ru2Cl10O·16H2O

Mg2Ru2Cl10O.16H2O {dimagnesium mu-oxo-bis[pentachlororuthenate(IV)] hexadecahydrate} crystallizes in the monoclinic system (space group P2(1)/c). The structure consists of layers of [Ru2Cl10O]4- anions, [Mg(H2O)6]2+ cations and water molecules stacked along the a axis. Only the O atom bonded to Ru occupies the 2a site with -1 symmetry. All the other atoms occupy general 4e sites. The crystal structure is stabilized by O-H...O and O-H...Cl interactions.