Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “coordination structure”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Structural organization of the spongy mesophyll

Summary Many plant leaves have two layers of photosynthetic tissue: the palisade and spongy mesophyll. Whereas palisade mesophyll consists of tightly packed columnar cells, the structure of spongy mesophyll is not well characterized and often treated as a random assemblage of irregularly shaped cells. Using micro‐computed tomography imaging, topological analysis, and a comparative physiological framework, we examined the structure of the spongy mesophyll in 40 species from 30 genera with laminar leaves and reticulate venation. A spectrum of spongy mesophyll diversity encompassed two dominant phenotypes: first, an ordered, honeycomblike tissue structure that emerged from the spatial coordination of multilobed cells, conforming to the physical principles of Euler’s law; and second, a less‐ordered, isotropic network of cells. Phenotypic variation was associated with transitions in cell size, cell packing density, mesophyll surface‐area‐to‐volume ratio, vein density, and maximum photosynthetic rate. These results show that simple principles may govern the organization and scaling of the spongy mesophyll in many plants and demonstrate the presence of structural patterns associated with leaf function. This improved understanding of mesophyll anatomy provides new opportunities for spatially explicit analyses of leaf development, physiology, and biomechanics.

3D↗
DOE OSTI2025

Affinity for OH – Produces Four-Coordinated Zn 2+ Impurities in Hydrated Amorphous Calcium Carbonate

Using ab initio based molecular dynamics and electronic structure calculations, we show that Zn impurities in hydrated amorphous calcium carbonate (ACC) have a much lower coordination number than other divalent impurities due to covalent interactions between the 3d Zn shell and the oxygen atoms of the carbonate and water groups. Further, the local structure around Zn in ACC, including the predicted low coordination number, is confirmed by X-ray absorption spectroscopy of synthetic Zn-bearing ACC. The strong Zn–O chemical interaction leads to substantial water dissociation and slightly disrupts the hydrogen bonding network. Implications of Zn 2+ incorporation for ACC stability are discussed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2010

Space-Frame Lunar Lander

The space-frame lunar lander was originally intended to (1) land on rough lunar terrain, (2) deform itself to conform to the terrain so as to be able to remain there in a stable position and orientation, and (3) if required, further deform itself to perform various functions. In principle, the space-frame lunar lander could be used in the same way on Earth, as might be required, for example, to place meteorological sensors or a radio-communication relay station on an otherwise inaccessible mountain peak. the space-frame lunar lander would include a truss-like structure consisting mostly of a tetrahedral mesh of nodes connected by variable-length struts, the lengths of which would be altered in coordination to impart the desired overall size and shape to the structure. Thrusters (that is, small rocket engines), propellant tanks, a control system, and instrumentation would be mounted in and on the structure (see figure). Once it had landed and deformed itself to the terrain through coordinated variations in the lengths of the struts, the structure could be further deformed into another space-frame structure

Curtis, Steven A.↗
DOE OSTI2025

Scalable mechanochemical synthesis of high-quality Prussian blue analogues for high-energy and durable potassium-ion batteries

Prussian blue analogues (PBAs) are recognized as promising cathode materials for potassium-ion batteries (PIBs), particularly the low-cost and high-energy K 2 Mn[Fe(CN) 6 ](KMnF). However, conventional solution-based synthesis inevitably introduces [Fe(CN) 6 ] 4− defects and lattice water while suffering low synthesis efficiency, unfavorable to the improvement of electrochemical performance and scalability. Here, in this work, we report a simple solvent-free mechanochemical strategy for the synthesis of a wide variety of K 2 M[Fe(CN) 6 ] (M = Mn, Mg, Ca, etc.) with negligible defects and water, and it is unprecedented to achieve kilogram-level products of high-quality KMnF within just 10 minutes. The as-prepared KMnF delivers a high energy density of 590 Wh kg −1 at 0.2 C and exhibits an astonishing stability over 10 000 cycles and rate ability up to 50 C in a potassium metal half-cell. Encouragingly, a high-areal-capacity pouch cell with 2.2 mAh cm −2 (16.5 mg cm −2 ) exhibits a capacity retention of 80.7% after 500 cycles. Furthermore, systematic in situ characterization reveals underlying mechanism insights into structure–performance relationships. Specifically, the fully coordinated Mn–N 6 octahedral configuration effectively suppresses Mn 3+ Jahn–Teller distortion, enabling reversible phase transitions under both high-voltage and long-term cycling conditions. In addition, minimal defects provide sufficient redox centers, while the continuous three-dimensional framework facilitates rapid K + diffusion kinetics. This work provides a new opportunity for the ultrafast, universal and scalable synthesis of high-quality PBAs, facilitating the practical application of PIBs while enabling precise structural and compositional design of novel PBAs.

Mechanochemical method↗
DOE OSTI2023

The Crystal Structure of BaZn 2 Se 2 (OH) 2 Featuring Brownmillerite‐Type Layers

Abstract A bimetallic hydroxychalcogenide, BaZn 2 Se 2 (OH) 2 , was synthesized through hydrothermal pouch methods. The single crystal X‐ray diffraction and electron diffraction indicates that the phase crystallizes in the orthorhombic space group Pnma and is composed of anionic layers [ZnSe 3/3 (OH) 1/1 ] − that are separated and charged balanced by Ba 2+ cations. The [ZnSe 3/3 (OH) 1/1 ] – layer comprises two unique Zn sites, which form interpenetrating zigzag chains with an in‐plane dipole moment and adopts a brownmillerite‐type structural motif. The adjacent layers contain tetrahedrally coordinated Zn chains of opposite handedness related by an inversion center, which cancel the microscopic dipoles to minimize the macroscopic electric polarization. The adoption of a brownmillerite structural motif in BaZn 2 Se 2 (OH) 2 can be rationalized by the distinct charge difference between Se 2− and OH − anions, which creates a sufficient dipole moment in the ZnSe 3 (OH) tetrahedra to allow the occurrence of twisted chains. FTIR spectroscopy confirms the existence of OH − anions and DFT calculations indicate that BaZn 2 Se 2 (OH) 2 is a semiconductor with a direct band gap. This work expands the chemistry of the brownmillerite family from traditional homoanionic oxides to multianion hydroxychalcogenides, offering a new opportunity to explore tunable structural complexity for better design of functional materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Eco-friendly, solution-processable and efficient low-energy lighting phosphors: copper halide based hybrid semiconductors Cu 4 X 6 (L) 2 (X = Br, I) composed of covalent, ionic and coordinate bonds

A series of copper halide based inorganic–organic hybrid semiconductors have been synthesized. Structural analysis confirms that all compounds are composed of one-dimensional Cu 4 X 6 2- anionic chains that coordinate to cationic ligands via Cu–N dative bonds. Different coordination affinities of the ligands lead to two types of ligand arrangements with various structural distortions. All compounds are highly resistant to heat and moisture as a result of the combination of coordinate and ionic bonds. Low energy emission with high efficiency is achieved for these compounds and the emission energy (~552–615 nm) and color (yellow-orange) can be tuned by varying the ligand and halogen element. The electronic structure and luminescence mechanism are examined by both experimental and theoretical methods. More importantly, all compounds demonstrate good solubility in polar aprotic solvents, a desired property that is absent in all other CuX hybrid families of extended structures, which is attributed primarily to the ionic nature of this material class. Furthermore, the good solution-processability, and cost effective and easily scalable synthesis coupled with high quantum efficiencies and framework stability make these hybrid materials promising phosphors for general lighting applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Coordination Chemistry of Solvated Metal Ions in Soft Donor Solvents

The structures of hexaammine solvated indium(III) and thallium(III) ions in liquid ammonia solution are determined by EXAFS. Both complexes have regular octahedral coordination geometry with mean In-N and Tl-N bond distances of 2.23(1) and 2.29(2) Å, respectively. Ammine solvated thallium(III) in liquid ammonia is characterized with 205Tl NMR measurements. Solvents such as liquid ammonia, N,N-dimethylthioformamide (DMTF), trialkyl and triphenyl phosphite and phosphine are strong electron pair donors and thereby able to form bonds with a large covalent contribution with strong electron pair acceptors. A survey of reported structures of ammine, DMTF, trialkyl and triphenyl phosphite and phosphine solvated metal ions in the solid state and solution is presented. The M-N and M-S bond distances in ammine and DMTF solvated metal ions are compared with the M-O bond distance in the corresponding metal ion hydrates, expected to form mainly electrostatic interactions with metal ions. The d10 metal ions have high ability to form bonds with a high degree of covalency with increasing ability down the group and with decreasing charge of the metal ion. The difference in M-N and M-O bond distances between ammine solvated and hydrated metal ions with the same coordination geometry decreases significantly with the increasing ability of the metal ion to form bonds with a large covalent contribution. This difference correlates well with the covalent bonding index, γM2*r.

Biochemistry & Molecular Biology↗
DOE OSTI2020

Materials Data on Li10Si(PSe6)2 by Materials Project

Li10Si(PSe6)2 is Aluminum carbonitride-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twenty inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.61–2.84 Å. In the second Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.66–3.30 Å. In the third Li1+ site, Li1+ is bonded to six Se2- atoms to form distorted LiSe6 octahedra that share a cornercorner with one LiSe6 octahedra, corners with two equivalent PSe4 tetrahedra, corners with three LiSe4 tetrahedra, corners with two equivalent LiSe5 trigonal bipyramids, an edgeedge with one SiSe4 tetrahedra, an edgeedge with one PSe4 tetrahedra, and edges with two LiSe4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Li–Se bond distances ranging from 2.67–3.19 Å. In the fourth Li1+ site, Li1+ is bonded to six Se2- atoms to form LiSe6 octahedra that share corners with two equivalent PSe4 tetrahedra, corners with four LiSe4 tetrahedra, an edgeedge with one LiSe6 octahedra, an edgeedge with one SiSe4 tetrahedra, an edgeedge with one PSe4 tetrahedra, edges with four LiSe4 tetrahedra, and an edgeedge with one LiSe5 trigonal bipyramid. There are a spread of Li–Se bond distances ranging from 2.66–3.02 Å. In the fifth Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two equivalent LiSe6 octahedra, corners with two equivalent LiSe4 tetrahedra, corners with two PSe4 tetrahedra, an edgeedge with one LiSe6 octahedra, an edgeedge with one LiSe4 tetrahedra, an edgeedge with one SiSe4 tetrahedra, and an edgeedge with one LiSe5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 18–61°. There are a spread of Li–Se bond distances ranging from 2.47–2.61 Å. In the sixth Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.65–3.34 Å. In the seventh Li1+ site, Li1+ is bonded to four Se2- atoms to form distorted LiSe4 tetrahedra that share a cornercorner with one LiSe6 octahedra, corners with two LiSe4 tetrahedra, corners with two PSe4 tetrahedra, corners with two LiSe5 trigonal bipyramids, an edgeedge with one LiSe6 octahedra, and an edgeedge with one SiSe4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of Li–Se bond distances ranging from 2.55–2.62 Å. In the eighth Li1+ site, Li1+ is bonded to six Se2- atoms to form LiSe6 octahedra that share a cornercorner with one LiSe6 octahedra, corners with two PSe4 tetrahedra, corners with six LiSe4 tetrahedra, an edgeedge with one LiSe6 octahedra, an edgeedge with one LiSe4 tetrahedra, an edgeedge with one SiSe4 tetrahedra, and an edgeedge with one PSe4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Li–Se bond distances ranging from 2.67–3.21 Å. In the ninth Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two LiSe6 octahedra, a cornercorner with one SiSe4 tetrahedra, a cornercorner with one PSe4 tetrahedra, corners with two equivalent LiSe4 tetrahedra, an edgeedge with one LiSe4 tetrahedra, and an edgeedge with one PSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–71°. There are a spread of Li–Se bond distances ranging from 2.50–2.64 Å. In the tenth Li1+ site, Li1+ is bonded to five Se2- atoms to form LiSe5 trigonal bipyramids that share corners with two equivalent LiSe6 octahedra, a cornercorner with one PSe4 tetrahedra, corners with two equivalent SiSe4 tetrahedra, corners with three LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one PSe4 tetrahedra, and edges with two LiSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–43°. There are a spread of Li–Se bond distances ranging from 2.56–3.05 Å. In the eleventh Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with four LiSe6 octahedra, a cornercorner with one SiSe4 tetrahedra, a cornercorner with one PSe4 tetrahedra, corners with two equivalent LiSe4 tetrahedra, an edgeedge with one LiSe4 tetrahedra, and an edgeedge with one PSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 17–68°. There are a spread of Li–Se bond distances ranging from 2.49–2.74 Å. In the twelfth Li1+ site, Li1+ is bonded to four Se2- atoms to form distorted LiSe4 tetrahedra that share corners with two LiSe6 octahedra, corners with two PSe4 tetrahedra, corners with four LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one SiSe4 tetrahedra, and an edgeedge with one LiSe5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 51–73°. There are a spread of Li–Se bond distances ranging from 2.60–2.80 Å. In the thirteenth Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two SiSe4 tetrahedra, corners with three LiSe4 tetrahedra, corners with three LiSe5 trigonal bipyramids, edges with two LiSe6 octahedra, and an edgeedge with one PSe4 tetrahedra. There are a spread of Li–Se bond distances ranging from 2.58–2.70 Å. In the fourteenth Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two equivalent LiSe4 tetrahedra, corners with two PSe4 tetrahedra, corners with two equivalent LiSe5 trigonal bipyramids, an edgeedge with one LiSe6 octahedra, an edgeedge with one LiSe4 tetrahedra, and an edgeedge with one SiSe4 tetrahedra. There are a spread of Li–Se bond distances ranging from 2.54–2.70 Å. In the fifteenth Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.50–2.62 Å. In the sixteenth Li1+ site, Li1+ is bonded to five Se2- atoms to form distorted LiSe5 trigonal bipyramids that share a cornercorner with one PSe4 tetrahedra, corners with two SiSe4 tetrahedra, corners with seven LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one LiSe6 octahedra, an edgeedge with one LiSe4 tetrahedra, and an edgeedge with one PSe4 tetrahedra. There are a spread of Li–Se bond distances ranging from 2.61–3.05 Å. In the seventeenth Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two equivalent LiSe6 octahedra, corners with two SiSe4 tetrahedra, corners with four LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one LiSe6 octahedra, and an edgeedge with one PSe4 tetrahedra. The corner-sharing octahedral tilt angles are 24°. There are a spread of Li–Se bond distances ranging from 2.60–2.71 Å. In the eighteenth Li1+ site, Li1+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.55–2.77 Å. In the nineteenth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Li–Se bond distances ranging from 2.54–3.12 Å. In the twentieth Li1+ site, Li1+ is bonded to four Se2- atoms to form distorted LiSe4 tetrahedra that share a cornercorner with one SiSe4 tetrahedra, a cornercorner with one PSe4 tetrahedra, corners with three LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one LiSe6 octahedra, an edgeedge with one PSe4 tetrahedra, and an edgeedge with one LiSe5 trigonal bipyramid. There are a spread of Li–Se bond distances ranging from 2.61–2.71 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four Se2- atoms to form SiSe4 tetrahedra that share corners with four LiSe4 tetrahedra, a cornercorner with one LiSe5 trigonal bipyramid, an edgeedge with one LiSe6 octahedra, and edges with two LiSe4 tetrahedra. There are a spread of Si–Se bond distances ranging from 2.30–2.32 Å. In the second Si4+ site, Si4+ is bonded to four Se2- atoms to form SiSe4 tetrahedra that share corners with three LiSe4 tetrahedra, corners with three LiSe5 trigonal bipyramids, edges with two LiSe6 octahedra, and edges with two LiSe4 tetrahedra. There are a spread of Si–Se bond distances ranging from 2.28–2.33 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four Se2- atoms to form PSe4 tetrahedra that share corners with three LiSe6 octahedra and corners with four LiSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–55°. There are a spread of P–Se bond distances ranging from 2.21–2.25 Å. In the second P5+ site, P5+ is bonded to four Se2- atoms to form PSe4 tetrahedra that share corners with three LiSe6 octahedra, corners with three LiSe4 tetrahedra, edges with two LiSe4 tetrahedra, and edges with two LiSe5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 29–58°. There are a spread of P–Se bond distances ranging from 2.22–2.25 Å. In the third P5+ site, P5+ is bonded to four Se2- atoms to form PSe4 tetrahedra that share corners with two LiSe4 tetrahedra, corners with two LiSe5 trigonal bipyramids, and an edgeedge with one LiSe4 tetrahedra. There are a spread of P–Se bond distances ranging from 2.23–2.25 Å. In the fourth P5+ site, P5+ is bonded to four Se2- atoms to form PSe4 tetrahedra that share corners with two LiSe4 tetrahedra, edges with three LiSe6 octahedra, and edges with two LiSe4 tetrahedra. There are a spread of P–Se bond distances ranging from 2.23–2.25 Å. There are twenty-four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one P5+ atom. In the second Se2- site, Se2- is bonded to four Li1+ and one P5+ atom to form distorted SeLi4P square pyramids that share a cornercorner with one SeLi4P square pyramid, corners with two SeLi4P trigonal bipyramids, a cornercorner with one SeLi3P trigonal pyramid, and edges with three SeLi4P trigonal bipyramids. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one P5+ atom. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one P5+ atom. In the fifth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Li1+ and one P5+ atom. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one P5+ atom. In the seventh Se2- site, Se2- is bonded to four Li1+ and one P5+ atom to form distorted SeLi4P trigonal bipyramids that share corners with two SeLi3P trigonal pyramids, an edgeedge with one SeLi4P square pyramid, and edges with two SeLi4P trigonal bipyramids. In the eighth Se2- site, Se2- is bonded in a distorted see-saw-like geometry to three Li1+ and one P5+ atom. In the ninth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one Si4+ atom. In the tenth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Li1+ and one Si4+ atom. In the eleventh Se2- site, Se2- is bonded in a 5-coordinate geometry to four Li1+ and one P5+ atom. In the twelfth Se2- site, Se2- is bonded to three Li1+ and one P5+ atom to form SeLi3P trigonal pyramids that share a cornercorner with one SeLi4P square pyramid, corners with two SeLi4Si trigonal bipyramids, and an edgeedge with one SeLi3P trigonal pyramid. In the thirteenth Se2- site, Se2- is bonded to four Li1+ and one P5+ atom to form distorted SeLi4P trigonal bipyramids that share a cornercorner with one SeLi4P square pyramid, corners with two SeLi4Si trigonal bipyramids, edges with two SeLi4P square pyramids, edges with two SeLi4P trigonal bipyramids, and an edgeedge with one SeLi3P trigonal pyramid. In the fourteenth Se2- site, Se2- is bonded to three Li1+ and one P5+ atom to form a mixture of edge and corner-sharing SeLi3P trigonal pyramids. In the fifteenth Se2- site, Se2- is bonded in a 5-coordinate

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li3Sb3(PO4)4 by Materials Project

Li3Sb3(PO4)4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are nine inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.75 Å. In the second Li1+ site, Li1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Li–O bond distances ranging from 1.95–2.73 Å. In the third Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.93–2.48 Å. In the fourth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.94–2.62 Å. In the fifth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share a cornercorner with one SbO5 square pyramid and corners with six PO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.09–2.29 Å. In the sixth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share a cornercorner with one SbO5 square pyramid and corners with six PO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.06–2.37 Å. In the seventh Li1+ site, Li1+ is bonded to six O2- atoms to form distorted LiO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.95–2.54 Å. In the eighth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 1.93–2.57 Å. In the ninth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.02–2.39 Å. There are nine inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded to five O2- atoms to form distorted SbO5 square pyramids that share a cornercorner with one LiO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of Sb–O bond distances ranging from 2.06–2.42 Å. In the second Sb3+ site, Sb3+ is bonded to five O2- atoms to form distorted SbO5 square pyramids that share a cornercorner with one LiO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 66°. There are a spread of Sb–O bond distances ranging from 2.06–2.45 Å. In the third Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.04–2.63 Å. In the fourth Sb3+ site, Sb3+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 2.04–2.27 Å. In the fifth Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.03–2.71 Å. In the sixth Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.02–2.60 Å. In the seventh Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.02–2.67 Å. In the eighth Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.04–2.71 Å. In the ninth Sb3+ site, Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.06–2.61 Å. There are twelve inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 24–54°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one LiO6 octahedra and an edgeedge with one SbO5 square pyramid. The corner-sharing octahedral tilt angles are 49°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra. The corner-sharing octahedra tilt angles range from 41–45°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one LiO6 octahedra and an edgeedge with one SbO5 square pyramid. The corner-sharing octahedral tilt angles are 52°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 28–30°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 23–42°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 29–33°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three LiO6 octahedra. The corner-sharing octahedra tilt angles range from 28–49°. There are a spread of P–O bond distances ranging from 1.52–1.59 Å. In the ninth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra. The corner-sharing octahedra tilt angles range from 42–45°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. In the tenth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 19–49°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. In the eleventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two LiO6 octahedra and a cornercorner with one SbO5 square pyramid. The corner-sharing octahedra tilt angles range from 28–39°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. In the twelfth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three LiO6 octahedra. The corner-sharing octahedra tilt angles range from 15–44°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. There are forty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one Sb3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a T-shaped geometry to two Li1+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Sb3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Sb3+ and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Sb3+ and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+ and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a T-shaped geometry to two Li1+ and one P5+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the twenty-ninth O2- site, O2- is bonded in a 2-coordinate geometry to two Sb3+ and one P5+ atom. In the thirtieth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-first O2- site, O2- is bonded in a 3-coordinate geometry to two Sb3+ and one P5+ atom. In the thirty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+ and one P5+ atom. In the thirty-fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the thirty-ninth O2- site, O2- is bonded in a 3-coordinate geometry to two Li1+ and one P5+ atom. In the fortieth O2- site, O2- is bonded in a 2-coordinate geometry to two Sb3+ and one P5+ atom. In the forty-first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Sb3+, and one P5+ atom. In the forty-second O2- site, O2- is bonded in a T-shaped geometry to two Li1+ and one P5+ atom. In the forty-third O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Sb3+, and one P5+ atom. In the forty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the forty-fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Sb3+, and one P5+ atom. In the forty-sixth O2- site, O2- is bonded in a 3-coordin

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li4TiMn8O18 by Materials Project

Li4TiMn8O18 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are eight inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.14–2.38 Å. In the second Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.20–2.59 Å. In the third Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.20–2.59 Å. In the fourth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.13–2.38 Å. In the fifth Li1+ site, Li1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.12 Å) and two longer (2.18 Å) Li–O bond lengths. In the sixth Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.24–2.65 Å. In the seventh Li1+ site, Li1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Li–O bond distances ranging from 2.24–2.64 Å. In the eighth Li1+ site, Li1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.12 Å) and two longer (2.18 Å) Li–O bond lengths. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent MnO6 octahedra, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 1.89–2.09 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent MnO6 octahedra, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 1.90–2.09 Å. There are sixteen inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–2.05 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.95–2.05 Å. In the third Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Mn–O bond distances ranging from 1.97–2.08 Å. In the fourth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.93–1.97 Å. In the fifth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. There is two shorter (1.92 Å) and four longer (1.95 Å) Mn–O bond length. In the sixth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–1.96 Å. In the seventh Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.94–1.97 Å. In the eighth Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Mn–O bond distances ranging from 1.96–2.08 Å. In the ninth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Mn–O bond distances ranging from 1.95–2.06 Å. In the tenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form edge-sharing MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.92–2.05 Å. In the eleventh Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–65°. There are four shorter (1.97 Å) and one longer (2.11 Å) Mn–O bond lengths. In the twelfth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Mn–O bond distances ranging from 1.95–2.05 Å. In the thirteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.97 Å. In the fourteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.93–1.97 Å. In the fifteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with two equivalent MnO5 square pyramids, and edges with four MnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are a spread of Mn–O bond distances ranging from 1.95–2.02 Å. In the sixteenth Mn+3.50+ site, Mn+3.50+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with six MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–65°. There are four shorter (1.97 Å) and one longer (2.11 Å) Mn–O bond lengths. There are thirty-six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.50+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.50+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.50+ atoms to form distorted OLi2Mn3 trigonal bipyramids that share corners with six OLiMn3 trigonal pyramids and edges with two equivalent OLi2Mn3 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the sixth O2- site, O2- is bonded to one Li1+ and three Mn+3.50+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four OLi2Mn3 trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids. In the seventh O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.50+ atoms to form OLi2Mn3 square pyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, edges with two equivalent OLi2Mn3 square pyramids, an edgeedge with one OLi2Mn3 trigonal bipyramid, and edges with two equivalent OLiMn3 trigonal pyramids. In the eighth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ti4+ and two equivalent Mn+3.50+ atoms. In the tenth O2- site, O2- is bonded to one Li1+ and three Mn+3.50+ atoms to form OLiMn3 trigonal pyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, corners with two equivalent OLiMn3 trigonal pyramids, and edges with two equivalent OLi2Mn3 square pyramids. In the eleventh O2- site, O2- is bonded to one Li1+ and three Mn+3.50+ atoms to form OLiMn3 trigonal pyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, corners with two equivalent OLiMn3 trigonal pyramids, and edges with two equivalent OLi2Mn3 square pyramids. In the twelfth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ti4+ and two equivalent Mn+3.50+ atoms. In the thirteenth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the fourteenth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.50+ atoms to form OLi2Mn3 square pyramids that share corners with two equivalent OLi2Mn3 trigonal bipyramids, edges with two equivalent OLi2Mn3 square pyramids, an edgeedge with one OLi2Mn3 trigonal bipyramid, and edges with two equivalent OLiMn3 trigonal pyramids. In the fifteenth O2- site, O2- is bonded to one Li1+ and three Mn+3.50+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four OLi2Ti2Mn trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the seventeenth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.50+ atoms to form distorted OLi2Mn3 trigonal bipyramids that share corners with six OLiMn3 trigonal pyramids and edges with two equivalent OLi2Mn3 trigonal bipyramids. In the eighteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+ and two equivalent Ti4+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.50+ atoms. In the twentieth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Mn+3.50+ atoms. In the twenty-first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Li1+ and two equivalent Mn+3.50+ atoms. In the twenty-second O2- site, O2- is bonded to two equivalent Li1+, two equivalent Ti4+, and one Mn+3.50+ atom to form distorted OLi2Ti2Mn trigonal bipyramids that share corners with four OLiMn3 trigonal pyramids and edges with two equivalent OLi2Ti2Mn trigonal bipyramids. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the twenty-fourth O2- site, O2- is bonded to one Li1+ and three Mn+3.50+ atoms to form distorted OLiMn3 trigonal pyramids that share corners with four OLi2Mn3 trigonal bipyramids and corners with two equivalent OLiMn3 trigonal pyramids. In the twenty-fifth O2- site, O2- is bonded to two equivalent Li1+ and three Mn+3.50+ atoms to form a mixture of edge and corner-sharing OLi2Mn3 trigonal bipyramids. In the twenty-sixth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Li1+ and three Mn+3.50+ atoms. In the twenty-seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.50+ atoms. In the twenty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two equivalent Mn+3.50+ atoms. In the twenty-ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ti4+ and two equivalent Mn+3.50+ atoms. In the thirtieth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn+3.50+ atoms. In the thirty-first O2- site, O2- is bonded in a 5-coordinate

36 MATERIALS SCIENCE↗
DOE OSTI2024

Coordination of copper within a crystalline carbon nitride and its catalytic reduction of CO 2

Inherently disordered structures of carbon nitrides have hindered an atomic level tunability and understanding of their catalytic reactivity. Starting from a crystalline carbon nitride, poly(triazine imide) or PTI/LiCl, the coordination of copper cations to its intralayer N-triazine groups was investigated using molten salt reactions. The reaction of PTI/LiCl within CuCl or eutectic KCl/CuCl 2 molten salt mixtures at 280 to 450 °C could be used to yield three partially disordered and ordered structures, wherein the Cu cations are found to coordinate within the intralayer cavities. Local structural differences and the copper content, i.e., whether full or partial occupancy of the intralayer cavity occurs, were found to be dependent on the reaction temperature and Cu-containing salt. Crystallites of Cu-coordinated PTI were also found to electrophoretically deposit from aqueous particle suspensions onto either graphite or FTO electrodes. As a result, electrocatalytic current densities for the reduction of CO 2 and H 2 O reached as high as ∼10 to 50 mA cm −2 , and remained stable for >2 days. Selectivity for the reduction of CO 2 to CO vs. H 2 increases for thinner crystals as well as for when two Cu cations coordinate within the intralayer cavities of PTI. Mechanistic calculations have also revealed the electrocatalytic activity for CO 2 reduction requires a smaller thermodynamic driving force with two neighboring Cu atoms per cavity as compared to a single Cu atom. These results thus establish a useful synthetic pathway to metal-coordination in a crystalline carbon nitride and show great potential for mediating stable CO 2 reduction at sizable current densities.

Chemistry↗
DOE OSTI2020

Using Complementary Methods of Synchrotron Radiation Powder Diffraction and Pair Distribution Function to Refine Crystal Structures with High Quality Parameters—A Review

Determination of the atomic-scale structures of certain fine-grained minerals using single-crystal X-ray diffraction (XRD) has been challenging because they commonly occur as submicron and nanocrystals in the geological environment. Synchrotron powder diffraction and scattering techniques are useful complementary methods for studying this type of minerals. In this review, we discussed three example studies investigated by combined methods of synchrotron radiation XRD and pair distribution function (PDF) techniques: (1) low-temperature cristobalite; (2) kaolinite; and (3) vernadite. Powder XRD is useful to determine the average structure including unit-cell parameters, fractional atomic coordinates, occupancies and isotropic atomic displacement parameters. X-ray/Neutron PDF methods are sensitive to study the local structure with anisotropic atomic displacement parameters (ADP). The results and case studies suggest that the crystal structure and high-quality ADP values can be obtained using the combined methods. The method can be useful to characterize crystals and minerals that are not suitable for single-crystal XRD.

58 GEOSCIENCES↗
DOE OSTI2023

Selective scandium ion capture through coordination templating in a covalent organic framework

The use of coordination complexes within covalent organic frameworks can significantly diversify the structures and properties of this class of materials. In this report we combined coordination chemistry and reticular chemistry by preparing frameworks that consist of a ditopic (p-phenylenediamine) and mixed tritopic moieties-an organic ligand and a scandium coordination complex of similar sizes and geometries, both bearing terminal phenylamine groups. Changing the ratio of organic ligand to scandium complex enabled the preparation of a series of crystalline covalent organic frameworks with tunable levels of scandium incorporation. Removal of scandium from the material with the highest metal content subsequently resulted in a 'metal-imprinted' covalent organic framework that exhibits a high affinity and capacity for Sc 3+ ions in acidic environments and in the presence of competing metal ions. In particular, the selectivity of this framework for Sc 3+ over common impurity ions such as La 3+ and Fe 3+ surpasses that of existing scandium adsorbents.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1993

On structuring the rules of a fuzzy controller

Since the pioneering work of Zadeh and Mamdani and Assilian, fuzzy logic control has emerged as one of the most active and fruitful research areas. The applications of fuzzy logic control can be found in many fields such as control of stream generators, automatic train operation systems, elevator control, nuclear reactor control, automobile transmission control, etc. In this paper, two new structures of hierarchical fuzzy rule-based controller are proposed to reduce the number of rules in a complete rule set of a controller. In one approach, the overall system is split into sub-systems which are treated independently in parallel. A coordinator is then used to take into account the interactions. This is done via an iterating information exchange between the lower level and the coordinator level. From the point of view of information used, this structure is very similar to central structure in that the coordinator can have at least in principle, all the information that the local controllers have.

Zhou, Jun↗
NASA NTRS1992

Integrated controls-structures optimization of a large space structure

General-purpose control and structural codes are applied to a large detailed structural model including objective and constraint functions derived from actual design specifications. The approach is to divide the problem into a controls optimization step, a structural optimization step, and a system level coordination step. The objective is to minimize mass and power consumption with constraints on vibration characteristics, strength, and damping. This decomposition and optimization approach significantly enhances the design of a structure based on the COFS-I Mast Flight System, which is selected as a demonstration problem.

Pasula, S. L.↗
DOE OSTI2020

Resolving the Atomic Structure of Sequential Infiltration Synthesis Derived Inorganic Clusters

Sequential infiltration synthesis (SIS) is a route to the precision deposition of inorganic solids in analogy to atomic layer deposition but occurs within (vs upon) a soft material template. SIS has enabled exquisite nanoscale morphological complexity in various oxides through selective nucleation in block copolymers templates. However, the earliest stages of SIS growth remain unresolved, including the atomic structure of nuclei and the evolution of local coordination environments, before and after polymer template removal. We employed In K-edge extended X-ray absorption fine structure and atomic pair distribution function analysis of high-energy X-ray scattering to unravel (1) the structural evolution of InO x H y clusters inside a poly(methyl methacrylate) (PMMA) host matrix and (2) the formation of porous In 2 O 3 solids (obtained after annealing) as a function of SIS cycle number. Early SIS cycles result in InO x H y cluster growth with high aspect ratio, followed by the formation of a three-dimensional network with additional SIS cycles. That the atomic structures of the InO x H y clusters can be modeled as multinuclear clusters with bonding patterns related to those in In 2 O 3 and In(OH) 3 crystal structures suggests that SIS may be an efficient route to 3D arrays of discrete-atom-number clusters. As a result, annealing the mixed inorganic/polymer films in air removes the PMMA template and consolidates the as-grown clusters into cubic In 2 O 3 nanocrystals with structural details that also depend on SIS cycle number.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1999

Visual-vestibular integration as a function of adaptation to space flight and return to Earth

Research on perception and control of self-orientation and self-motion addresses interactions between action and perception . Self-orientation and self-motion, and the perception of that orientation and motion are required for and modified by goal-directed action. Detailed Supplementary Objective (DSO) 604 Operational Investigation-3 (OI-3) was designed to investigate the integrated coordination of head and eye movements within a structured environment where perception could modify responses and where response could be compensatory for perception. A full understanding of this coordination required definition of spatial orientation models for the microgravity environment encountered during spaceflight.

Reschke, Millard R.↗