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Structure and Reactivity of a High-Spin, Nonheme Iron(III)- Superoxo Complex Supported by Phosphinimide Ligands
Nonheme iron oxygenases utilize dioxygen to accomplish challenging chemical oxidations. Additionally, a further understanding of the Fe-O 2 intermediates implicated in these processes is challenged by their highly transient nature. To that end, we have developed a ligand platform featuring phosphinimide donors intended to stabilize oxidized, high-spin iron complexes. O 2 exposure of single crystals of a three-coordinate Fe(II) complex of this framework allowed for in crystallo trapping of a terminally bound Fe-O 2 complex suitable for XRD characterization. Spectroscopic and computational studies of this species support a high-spin Fe(III) center antiferromagnetically coupled to a superoxide ligand, similar to that proposed for numerous nonheme iron oxygenases. In addition to the apparent stability of this synthetic Fe-O 2 complex, its ability to engage in a range of stoichiometric and catalytic oxidation processes demonstrates that this iron-phosphinimide system is primed for development in modeling oxidizing bioinorganic intermediates and green oxidation chemistry.
Equilibrium distribution of point defects in Fe-Y-O as a typical representative of nanocluster-strengthened alloys
The statistical mechanic approach has been used to estimate the equilibrium defect distribution in a multiphase system by minimizing its free energy using microstructural characteristics and a finite set of defects obtained by first-principles calculations. Recently the approach was extended to take in consideration defects at the interface of the precipitate and matrix. Herein we apply the developed approach to the investigation of the stability of bcc Fe containing yttria, Y 2 O 3 , nanoclusters as a prototype of nanostructured ferritic alloys. It has been obtained that (100)Fe-O interface is unstable with respect to vacancies production. In a contrast to (100)Fe-O interface, the so called Klim interface is stable, i.e. local vacancy concentration at this interface at 600 K is below 10 -12 . It has been demonstrated that due to large defect formation energies the ODS particles are extremely stable and the main defect corresponds to Fe atoms substitute Y in Y 2 O 3 precipitate. Moreover, under thermodynamic equilibrium condition, the preexist vacancies in bulk Fe do not accumulate oxygen atom. The later observation not necessarily forbid the existence of a large amount of preexisting Fe vacancy - oxygen atom clusters at the initial stages of alloy formation far from equilibrium.
Role of Fe Doping on Local Structure and Electrical and Magnetic Properties of PbTiO 3
In this work, the local structure and multiferroic properties of iron-doped lead titanate (PbTi 1-x Fe x O 3-δ ) samples was investigated over the entire composition range (x = 0-1). Inherent polarization in PbTiO 3 decreases due to Fe 3+ incorporation up to the solubility limit (x similar to 0.3), although homogeneous doping persists only up to x = 0.1. Ti prefers highly distorted oxygen octahedra for any x value, while Fe prefers more symmetric O-deficient polyhedra (Fe-O n ). The charge compensating oxygen vacancies induce local tilting of the Fe-O n polyhedra beyond a critical x value (x ≥ 0.2), promoting magnetic interaction between two adjacent Fe atoms. The strain induced by local heterogeneity could act as a coupling force between magnetic and ferroelectric properties. Fe-rich clusters evolve into ferromagnetic PbFe 12 O 19 with increased Fe doping. PbTi 1-x Fe x O 3-δ (x ≥ 0.3) samples therefore have separate origins for the ferroelectric (PbTi 1-x Fe x O 3-δ ) and magnetic (PbFe 12 O 19 ) phases.
Investigation of Sr[subscript 0.7]Ca[subscript 0.3]FeO[subscript 3] Oxygen Carriers with Variable Co
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Extending SLUSCHI for Automated Diffusion Calculations
We present an extension of the SLUSCHI package (Solid and Liquid in Ultra Small Coexistence with Hovering Interfaces) to enable automated diffusion calculations from first-principles molecular dynamics. While the original SLUSCHI workflow was designed for melting temperature estimation via solid-liquid coexistence, we adapt its input and output handling to isolate the volume search stage and generate one production trajectory suitable for diffusion analysis. Post-processing tools parse VASP outputs, compute mean-square displacements (MSD), and extract tracer diffusivities using the Einstein relation with robust error estimates through block averaging. Diagnostic plots, including MSD curves, running slopes, and velocity autocorrelations, are produced automatically to help identify diffusive regimes. The method has been validated through representative case studies: self-diffusion in Al-Cu liquid alloys, sublattice melting in Li7La3Zr2O12 and Er2O3, interstitial oxygen transport in bcc and fcc Fe, and oxygen diffusivity in Fe-O liquids with variable Si and Al contents. Viscosity and diffusivity are linked through the Stokes-Einstein relation, with composition dependence assessed via simple linear mixing. This capability broadens SLUSCHI from melting-point predictions to transport property evaluation, enabling high-throughput, fully first-principles datasets of diffusion coefficients and viscosities across metals and oxides.
Iron surface corrosion in supercritical CO2 at atomic scale investigated by molecular dynamics simulations
Understanding the corrosion behavior of steels in supercritical carbon dioxide (S-CO2) is essential for ensuring the safe application of S-CO2 as a heat-transfer fluid in high-temperature energy systems, including advanced nuclear reactors. In this work, molecular dynamics (MD) simulations using ReaxFF potential are performed to explore the atomic-scale corrosion mechanisms of body-centered cubic iron (BCC-Fe) in S-CO2. The results show that CO2 molecules in S-CO2 decompose at the Fe surface, generating free C and O atoms that form Fe-C and Fe-O bonds and subsequently produce oxides and carbides. Concurrently, Fe atoms dissolve from the surface and diffuse into the S-CO2 region, resulting in interdiffusion of Fe, C and O atoms at the interface. The corrosion-layer thickness calculations show that high pressure and temperature induced by S-CO2 have stronger effects than surface orientation on the corrosion process. In addition, surface Fe atoms undergo substantial displacement under S-CO2 exposure, further accelerating corrosion. When a radiation-induced void is introduced near the Fe surface, the corrosion is enhanced. The void-matrix interface expands the reaction surface area and simultaneously induces corrosion reactions inside the bulk, resulting in a deeper penetration of C and O and thicker corrosion layers. All these results indicate that high-temperature, high-pressure and radiation-induced voids can seriously affect the corrosion of Fe in S-CO2, and must be considered to better use S-CO2 in nuclear facilities.
Experimental electronic structures of the Fe IV =O bond in S=1 heme vs. nonheme sites: Effect of the porphyrin ligand
High-valent Fe IV =O species are common intermediates in biological and artificial catalysts. Heme and nonheme S=1 Fe IV =O sites have been synthesized and studied for decades but little quantitative experimental comparison of their electronic structures has been available, due to the lack of direct methods focused on the iron. This study allows a rigorous determination of the electronic structure of a nonheme Fe IV =O center and its comparison to an Fe IV =O heme site using 1s2p resonant inelastic X-ray scattering (RIXS) and Fe L-edge X-ray absorption spectroscopy (XAS). Further, variable temperature magnetic circular dichroism (VT-MCD) of the ligand field transitions, combined with nuclear resonance vibrational spectroscopy of the two S=1 Fe IV =O systems show that the equatorial ligand field decreases from a nonheme to a heme Fe IV =O site. Alternatively, RIXS and Fe L-edge XAS combined with MCD show that the Fe dπ orbitals are unperturbed in the Fe IV =O heme relative to the nonheme site because the strong axial Fe-O bond uncouples the Fe dπ orbitals from the porphyrin π-system. As a consequence, the thermodynamics and kinetics of the H-atom abstraction reactions are actually very similar for heme compound II and nonheme Fe IV =O active sites.
Materials Data on Fe3O4 by Materials Project
Fe3O4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.13 Å) and four longer (2.29 Å) Fe–O bond lengths. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 0–55°. There are a spread of Fe–O bond distances ranging from 1.97–2.10 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a square co-planar geometry to four equivalent Fe+2.67+ atoms. In the second O2- site, O2- is bonded to four Fe+2.67+ atoms to form distorted OFe4 tetrahedra that share corners with two equivalent OFe4 tetrahedra, corners with ten equivalent OFe5 trigonal bipyramids, and edges with two equivalent OFe5 trigonal bipyramids. In the third O2- site, O2- is bonded to five Fe+2.67+ atoms to form distorted OFe5 trigonal bipyramids that share corners with five equivalent OFe4 tetrahedra, corners with two equivalent OFe5 trigonal bipyramids, an edgeedge with one OFe4 tetrahedra, and edges with five equivalent OFe5 trigonal bipyramids.
Materials Data on FeO by Materials Project
FeO is Halite, Rock Salt structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Fe2+ is bonded to six equivalent O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.16 Å) and two longer (2.17 Å) Fe–O bond lengths. O2- is bonded to six equivalent Fe2+ atoms to form a mixture of edge and corner-sharing OFe6 octahedra. The corner-sharing octahedral tilt angles are 0°.
Materials Data on Fe3O4 by Materials Project
Fe3O4 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra and edges with six FeO6 octahedra. There are two shorter (2.08 Å) and four longer (2.11 Å) Fe–O bond lengths. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six equivalent O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra and edges with six equivalent FeO6 octahedra. All Fe–O bond lengths are 2.06 Å. In the third Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–57°. All Fe–O bond lengths are 1.92 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe+2.67+ atoms.
Materials Data on Fe3O4 by Materials Project
Fe3O4 is Hausmannite structured and crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. there are four inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.09–2.17 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–59°. There is two shorter (1.91 Å) and two longer (1.96 Å) Fe–O bond length. In the third Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.08 Å. In the fourth Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–58°. There is two shorter (1.90 Å) and two longer (1.98 Å) Fe–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms.
Materials Data on Fe7O8 by Materials Project
Fe7O8 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Fe+2.29+ sites. In the first Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. All Fe–O bond lengths are 2.15 Å. In the second Fe+2.29+ site, Fe+2.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. There are two shorter (2.19 Å) and four longer (2.20 Å) Fe–O bond lengths. In the third Fe+2.29+ site, Fe+2.29+ is bonded to six equivalent O2- atoms to form edge-sharing FeO6 octahedra. All Fe–O bond lengths are 2.05 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to six Fe+2.29+ atoms to form OFe6 octahedra that share corners with six equivalent OFe6 octahedra and edges with twelve equivalent OFe5 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to five Fe+2.29+ atoms to form OFe5 square pyramids that share corners with nine equivalent OFe5 square pyramids, edges with four equivalent OFe6 octahedra, and edges with four equivalent OFe5 square pyramids.
Materials Data on Fe3O4 by Materials Project
Fe3O4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–1.98 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–15°. There are a spread of Fe–O bond distances ranging from 2.05–2.22 Å. In the third Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–12°. There are a spread of Fe–O bond distances ranging from 2.00–2.14 Å. In the fourth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form edge-sharing FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–1.99 Å. In the fifth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–15°. There are a spread of Fe–O bond distances ranging from 2.11–2.22 Å. In the sixth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–15°. There are a spread of Fe–O bond distances ranging from 2.02–2.13 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the second O2- site, O2- is bonded to five Fe+2.67+ atoms to form a mixture of corner and edge-sharing OFe5 square pyramids. In the third O2- site, O2- is bonded to five Fe+2.67+ atoms to form a mixture of corner and edge-sharing OFe5 square pyramids. In the fourth O2- site, O2- is bonded in a see-saw-like geometry to four Fe+2.67+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the sixth O2- site, O2- is bonded to five Fe+2.67+ atoms to form a mixture of corner and edge-sharing OFe5 square pyramids. In the seventh O2- site, O2- is bonded to five Fe+2.67+ atoms to form a mixture of corner and edge-sharing OFe5 square pyramids. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms.
Materials Data on Fe3O4 by Materials Project
Fe3O4 is Hausmannite structured and crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are six inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.09–2.17 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.12 Å. In the third Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.04–2.07 Å. In the fourth Fe+2.67+ site, Fe+2.67+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.11–2.19 Å. In the fifth Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–62°. There are a spread of Fe–O bond distances ranging from 1.91–1.98 Å. In the sixth Fe+2.67+ site, Fe+2.67+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–60°. There are a spread of Fe–O bond distances ranging from 1.91–1.96 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the third O2- site, O2- is bonded to four Fe+2.67+ atoms to form distorted corner-sharing OFe4 trigonal pyramids. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.67+ atoms.
Materials Data on Fe35O36 by Materials Project
Fe35O36 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are thirty-five inequivalent Fe+2.06+ sites. In the first Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Fe–O bond distances ranging from 2.11–2.33 Å. In the second Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Fe–O bond distances ranging from 2.13–2.32 Å. In the third Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–7°. There are a spread of Fe–O bond distances ranging from 2.13–2.27 Å. In the fourth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–7°. There are a spread of Fe–O bond distances ranging from 2.12–2.24 Å. In the fifth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–11°. There are a spread of Fe–O bond distances ranging from 2.11–2.31 Å. In the sixth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–17°. There are a spread of Fe–O bond distances ranging from 2.10–2.24 Å. In the seventh Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Fe–O bond distances ranging from 2.09–2.30 Å. In the eighth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Fe–O bond distances ranging from 2.03–2.20 Å. In the ninth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Fe–O bond distances ranging from 2.12–2.22 Å. In the tenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–17°. There are a spread of Fe–O bond distances ranging from 2.08–2.33 Å. In the eleventh Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Fe–O bond distances ranging from 2.12–2.27 Å. In the twelfth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Fe–O bond distances ranging from 2.12–2.25 Å. In the thirteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Fe–O bond distances ranging from 2.07–2.26 Å. In the fourteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Fe–O bond distances ranging from 2.04–2.08 Å. In the fifteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–7°. There are a spread of Fe–O bond distances ranging from 2.14–2.20 Å. In the sixteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–13°. There are a spread of Fe–O bond distances ranging from 2.07–2.30 Å. In the seventeenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–8°. There are a spread of Fe–O bond distances ranging from 2.07–2.31 Å. In the eighteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 5–11°. There are a spread of Fe–O bond distances ranging from 2.09–2.25 Å. In the nineteenth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Fe–O bond distances ranging from 2.10–2.31 Å. In the twentieth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Fe–O bond distances ranging from 2.09–2.26 Å. In the twenty-first Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Fe–O bond distances ranging from 2.03–2.13 Å. In the twenty-second Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 7–12°. There are a spread of Fe–O bond distances ranging from 2.08–2.27 Å. In the twenty-third Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 4–14°. There are a spread of Fe–O bond distances ranging from 2.12–2.32 Å. In the twenty-fourth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–8°. There are a spread of Fe–O bond distances ranging from 2.07–2.24 Å. In the twenty-fifth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Fe–O bond distances ranging from 2.10–2.32 Å. In the twenty-sixth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Fe–O bond distances ranging from 2.13–2.22 Å. In the twenty-seventh Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–6°. There are a spread of Fe–O bond distances ranging from 2.10–2.37 Å. In the twenty-eighth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Fe–O bond distances ranging from 2.13–2.24 Å. In the twenty-ninth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Fe–O bond distances ranging from 2.15–2.27 Å. In the thirtieth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Fe–O bond distances ranging from 2.12–2.24 Å. In the thirty-first Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–14°. There are a spread of Fe–O bond distances ranging from 2.09–2.25 Å. In the thirty-second Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Fe–O bond distances ranging from 2.12–2.29 Å. In the thirty-third Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–10°. There are a spread of Fe–O bond distances ranging from 2.15–2.24 Å. In the thirty-fourth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–10°. There are a spread of Fe–O bond distances ranging from 2.08–2.32 Å. In the thirty-fifth Fe+2.06+ site, Fe+2.06+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Fe–O bond distances ranging from 2.09–2.33 Å. There are thirty-six inequivalent O2- sites. In the first O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra, edges with nine OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 1–12°. In the second O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eleven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid. The corner-sharing octahedra tilt angles range from 2–5°. In the third O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with six OFe6 octahedra, edges with nine OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 4–9°. In the fourth O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eleven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid. The corner-sharing octahedra tilt angles range from 1–7°. In the fifth O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with four OFe6 octahedra, corners with two OFe5 square pyramids, edges with ten OFe6 octahedra, and edges with two OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–7°. In the sixth O2- site, O2- is bonded to five Fe+2.06+ atoms to form OFe5 square pyramids that share corners with five OFe6 octahedra, corners with four OFe5 square pyramids, and edges with eight OFe6 octahedra. The corner-sharing octahedra tilt angles range from 1–12°. In the seventh O2- site, O2- is bonded to five Fe+2.06+ atoms to form OFe5 square pyramids that share corners with five OFe6 octahedra, corners with four OFe5 square pyramids, and edges with eight OFe6 octahedra. The corner-sharing octahedra tilt angles range from 1–10°. In the eighth O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eleven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid. The corner-sharing octahedra tilt angles range from 2–4°. In the ninth O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with four OFe6 octahedra, corners with two OFe5 square pyramids, edges with eleven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid. The corner-sharing octahedra tilt angles range from 1–4°. In the tenth O2- site, O2- is bonded to six Fe+2.06+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eleven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid.
Materials Data on Fe17O18 by Materials Project
Fe17O18 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are nine inequivalent Fe+2.12+ sites. In the first Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Fe–O bond distances ranging from 2.12–2.24 Å. In the second Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–12°. There are a spread of Fe–O bond distances ranging from 2.14–2.27 Å. In the third Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 3–12°. There are a spread of Fe–O bond distances ranging from 2.02–2.15 Å. In the fourth Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Fe–O bond distances ranging from 2.12–2.34 Å. In the fifth Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 6–14°. There are a spread of Fe–O bond distances ranging from 2.08–2.29 Å. In the sixth Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. There are a spread of Fe–O bond distances ranging from 2.11–2.36 Å. In the seventh Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 6–11°. There are a spread of Fe–O bond distances ranging from 2.14–2.26 Å. In the eighth Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Fe–O bond distances ranging from 2.04–2.31 Å. In the ninth Fe+2.12+ site, Fe+2.12+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedra tilt angles range from 2–14°. There are a spread of Fe–O bond distances ranging from 2.14–2.26 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eight OFe6 octahedra, and edges with four OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 3–8°. In the second O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eight OFe6 octahedra, and edges with four OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–9°. In the third O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with five OFe6 octahedra, a cornercorner with one OFe5 square pyramid, edges with eight OFe6 octahedra, and edges with four OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–9°. In the fourth O2- site, O2- is bonded to five Fe+2.12+ atoms to form OFe5 square pyramids that share corners with four OFe6 octahedra, corners with five OFe5 square pyramids, edges with seven OFe6 octahedra, and an edgeedge with one OFe5 square pyramid. The corner-sharing octahedra tilt angles range from 5–10°. In the fifth O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with four OFe6 octahedra, corners with two OFe5 square pyramids, edges with seven OFe6 octahedra, and edges with five OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 2–8°. In the sixth O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with two OFe6 octahedra, corners with four OFe5 square pyramids, edges with nine OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the seventh O2- site, O2- is bonded to five Fe+2.12+ atoms to form OFe5 square pyramids that share corners with three OFe6 octahedra, corners with six OFe5 square pyramids, and edges with eight OFe6 octahedra. The corner-sharing octahedra tilt angles range from 8–11°. In the eighth O2- site, O2- is bonded to five Fe+2.12+ atoms to form OFe5 square pyramids that share corners with five OFe6 octahedra, corners with four OFe5 square pyramids, and edges with eight OFe6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. In the ninth O2- site, O2- is bonded to six Fe+2.12+ atoms to form OFe6 octahedra that share corners with three OFe6 octahedra, corners with three OFe5 square pyramids, edges with nine OFe6 octahedra, and edges with three OFe5 square pyramids. The corner-sharing octahedra tilt angles range from 0–8°.
Materials Data on Fe2O3 by Materials Project
Fe2O3 is beta indium sulfide-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are thirteen inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Fe–O bond distances ranging from 1.88–1.97 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.11 Å. In the third Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.93–2.03 Å. In the fourth Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–62°. There are a spread of Fe–O bond distances ranging from 1.85–1.98 Å. In the fifth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra and edges with five FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.15 Å. In the sixth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with five FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.94–2.10 Å. In the seventh Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with three equivalent FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.18 Å. In the eighth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.96–2.13 Å. In the ninth Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Fe–O bond distances ranging from 1.88–2.01 Å. In the tenth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with five FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.95–2.09 Å. In the eleventh Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–62°. There is one shorter (1.92 Å) and three longer (1.96 Å) Fe–O bond length. In the twelfth Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four FeO4 tetrahedra and edges with six FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.97–2.09 Å. In the thirteenth Fe3+ site, Fe3+ is bonded to four O2- atoms to form corner-sharing FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–61°. There are a spread of Fe–O bond distances ranging from 1.91–1.96 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Fe3+ atoms. In the seventh O2- site, O2- is bonded in a trigonal planar geometry to three Fe3+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Fe3+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Fe3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the eleventh O2- site, O2- is bonded in a distorted T-shaped geometry to three Fe3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe3+ atoms. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted T-shaped geometry to three Fe3+ atoms. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe3+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Fe3+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Fe3+ atoms.