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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.

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At least 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Heating Ventilation Air-Conditioning (HVAC) System Analysis and Optimization for Revit with the OpenStudio Analytical Framework (CRADA Final Report)

This project proposes to integrate the NREL-developed OpenStudio (OS) and its accompanying Analytical Framework (OSAF) into Autodesk’s (ADSK’s) market leading suite of building information modeling (BIM) tools. As a result, BIM users will gain access to advanced (but user-friendly) building energy modeling (BEM), calibration, and design optimization capabilities. Following integration, the BIM software will automatically generate a consistent OS-based BEM model, allowing users to develop projects in an integrated manner, moving back and forth between architectural and engineering perspectives without redundancy or data loss, saving time and effort.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Distinct Clinical Impact and Biological Function of Angiopoietin and Angiopoietin-like Proteins in Human Breast Cancer

Secreted angiopoietin/angiopoietin-like (ANGPT/ANGPTL) proteins are involved in many biological processes. However, the role of these proteins in human breast cancers (BCs) remains largely unclear. Here, we conducted integrated omics analyses to evaluate the clinical impact of ANGPT/ANGPTL proteins and to elucidate their biological functions. In BCs, we identified rare mutations in ANGPT/ANGPTL genes, frequent gains of ANGPT1, ANGPT4, and ANGPTL1, and frequent losses of ANGPT2, ANGPTL5, and ANGPTL7, but observed that ANGPTL1, 2, and 4 were robustly downregulated in multiple datasets. The expression levels of ANGPTL1, 5, and 8 were positively correlated with overall survival (OS), while the expression levels of ANGPTL4 were negatively correlated with OS. Additionally, the expression levels of ANGPTL1 and 7 were positively correlated with distant metastasis-free survival (DMFS), while the expression levels of ANGPT2 and ANGPTL4 were negatively correlated with DMFS. The prognostic impacts of ANGPT/ANGPTL genes depended on the molecular subtypes and on clinical factors. We discovered that various ANGPT/ANGPTL genes were co-expressed with various genes involved in different pathways. Finally, with the exception of ANGPTL3, the remaining genes showed significant correlations with cancer-associated fibroblasts, endothelial cells, and microenvironment score, whereas only ANGPTL6 was significantly correlated with immune score. Our findings provide strong evidence for the distinct clinical impact and biological function of ANGPT/ANGPTL proteins, but the question of whether some of them could be potential therapeutic targets still needs further investigation in BCs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Surfactant-free syntheses and pair distribution function analysis of osmium nanoparticles

A surfactant-free synthesis of precious metal nanoparticles (NPs) performed in alkaline low-boiling-point solvents has been recently reported. Monoalcohols are here investigated as solvents and reducing agents to obtain colloidal Os nanoparticles by using low-temperature (<100 °C) surfactant-free syntheses. The effect of the precursor (OsCl 3 or H 2 OsCl 6 ), precursor concentration (up to 100 mM), solvent (methanol or ethanol), presence or absence of a base (NaOH), and addition of water (0 to 100 vol %) on the resulting nanomaterials is discussed. It is found that no base is required to obtain Os nanoparticles as opposed to the case of Pt or Ir NPs. The robustness of the synthesis for a precursor concentration up to 100 mM allows for the performance of X-ray total scattering with pair distribution function (PDF) analysis, which shows that 1–2 nm hexagonal close packed (hcp) NPs are formed from chain-like [OsO x Cl y ] complexes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

An evaluation of prognostic factors, oncologic outcomes, and management for primary and recurrent squamous cell carcinoma of the vulva

Objective: To evaluate prognostic factors, outcomes, and management patterns of patients treated for squamous cell carcinoma of the vulva. Methods: One hundred sixty-four women were retrospectively identified with primary squamous cell carcinoma of the vulva treated at our institution between 1/1996–12/2018. Descriptive statistics were performed on patient, tumor, and treatment characteristics. The χ 2 tests and t-tests were used to compare categorical variables and continuous variables, respectively. Recurrence free survival (RFS), overall survival (OS), and disease-specific survival (DSS) were analyzed with Kaplan-Meier estimates, the log-rank test, and Cox proportional hazards. Results: Median follow-up was 52.5 months. Five-year RFS was 67.9%, 60.0%, 42.1%, and 20.0% for stage I–IV, respectively. Five-year DSS was 86.2%, 81.6%, 65.0%, and 42.9% for stage I–IV, respectively. On multivariate analysis, positive margins predicted overall RFS (hazard ratio [HR]=3.55; 95% confidence interval [CI]=1.18–10.73; p=0.025), while presence of lichen sclerosus on pathology (HR=2.78; 95% CI=1.30–5.91; p=0.008) predicted local RFS. OS was predicted by nodal involvement (HR=2.51; 95% CI=1.02–6.13; p=0.043) and positive margins (HR=5.19; 95% CI=2.03–13.26; p=0.001). Adjuvant radiotherapy significantly improved RFS (p=0.016) and DSS (p=0.012) in node-positive patients. Median survival after treatment of local, groin, and pelvic/distant recurrence was 52, 8, and 5 months, respectively. Conclusion: For primary treatment, more conservative surgical approaches can be considered with escalation of treatment in patients with concurrent precursor lesions, positive margins, and/or nodal involvement. Further studies are warranted to improve risk stratification in order to optimize treatment paradigms for vulvar cancer patients.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Pressure-temperature effects on knock with iso-octane and propane at various compression ratios and intake temperatures

Knock remains one of the main limitations for increased internal combustion engine efficiency. Recent trends in light-duty vehicles towards downsized, boosted engines increases the need for improving the understanding between fuel chemistry and thermodynamic effects contributing to knock. Previous studies have shown the importance of end-gas thermodynamic conditions on knock onset and behavior, with relationships to fuel chemistry illustrated. However, a complete understanding of how fuels allow access to higher engine loads and the governing physics behind end-gas knock under a wide range of thermodynamic conditions is still unclear. Experiments in this work improve this understanding with the use of three fuels (1) iso-octane, a low octane sensitivity (OS) fuel (2) a Co-Optima aromatic core fuel, which has similar research octane number (RON) yet significantly higher OS, and (3) propane, known for its knock resistance. Engine load sweeps are conducted with each fuel while maintaining a CA50 of 8 crank angle degrees after top dead center (°CA aTDCf). As load increases and knock onset is observed, spark is delayed to its knock limited spark advance (KLSA) allowing further increases in load until either one of two limits is reached; (1) CA50 retard limit (2) Peak cylinder pressure limit. Experiments are conducted at 40°C and 90°C intake temperature and at two distinct compression ratios (rc) 9.2:1 and 13.6:1. Two-zone zero-dimensional simulations were performed in Chemkin to extract end-gas pressure and temperature conditions through the combustion process for each experimental condition of interest. CA50 response as a function of engine load is compared for all experimental conditions and fuels, and a pressure-temperature (PT) trajectory analysis is conducted using constant volume ignition delay contours to explain the behavior of each fuel.

Dal Forno Chuahy, Flavio↗
DOE OSTI2020

An Experimental Feasibility Study on Applying Neutron Tomography to Encapsulated Spent Nuclear Fuel - 20050

Visual inspection makes easier to ensure the integrity and safety of spent nuclear fuel (SNF) than any classical techniques. Various classical techniques have been applied but there are no reliable methods to qualitatively and quantitatively verify spent fuel in dry storage. Thus, the present authors have developed the prototype safeguards apparatus for dry storage employing the array of He-4 gas scintillation detectors (S670E, Arktis Radiation Detectors Ltd., Switzerland), newly designed to simultaneously measure thermal and fast neutrons without any moderators. The S670E detector has a cylindrical shape with a diameter of 52 mm and active length of 600 mm (total length: 875 mm). The detector is filled by He-4 gas with an approximate pressure of 180 bar for fast neutron detection, and its inner wall is coated by Li-6 for thermal neutron detection. The scintillation lights generated via Li-6 nuclear reaction and elastic scattering are collected by 24 SiPMs linearly paired at the center of the detector. The detector delivers a TTL (Transistor-Transistor Logic) output for pulse readout and UART (Universal Asynchronous Receiver Transmitter) for device control. In order to assess feasibility of the apparatus, an experimental system has been designed, built, and optimized via computational studies. Cf-252 neutron sources and linearly arrayed detectors, working as a single detector, were occupied for this study due to the difficulties in working with SNF. The laboratory scale cask (diameter: 0.67 m, height: 1.5 m), minimized by a factor of 10 compared to the actual thickness of a commercial TN-32 cask, was also manufactured. The detector array was designed to rotate the lab-scale cask and obtain 36 image profiles at every 10 degrees. All profiles were aligned in single frame image called a sinogram, and the cross-sectional image was then fabricated by the inverse radon transform algorithm. These experiments have been repeated with different configurations and numbers of sources. Some gamma-ray sources were also measured with neutron sources in order to distinguish between neutron and gamma-ray pulses. Basically, a He-4 detector is designed to run on Linux OS so it is difficult to directly apply to Windows-based equipment widely used in S. Korea. Therefore, a new data acquisition board working on Windows OS was designed and built. The board mainly consists of FPGA (Field Programmable Gate Array) and SoC (System on Chip) for TTL pulse readout, sorting measured data, and transferring data to a user interface. In conclusion, the tomographic system at lab-scale has shown considerable potential to detect a partial or gross defect of encapsulated assemblies in dry storage. Next steps of this study will be to 1) repeatedly carry out experiments to demonstrate scientific reliability and validity, and 2) numerically integrate signals with weight factors to enhance the image quality since the suggested system based on passive interrogation method requires longer measurement time. Finally, the system will apply to a commercial dry storage phased out soon in S. Korea. (authors)

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2020

Materials Data on SiOs by Materials Project

OsSi is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Os4+ is bonded in a body-centered cubic geometry to eight equivalent Si4- atoms. All Os–Si bond lengths are 2.56 Å. Si4- is bonded in a body-centered cubic geometry to eight equivalent Os4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2LiOsO6 by Materials Project

Ba2LiOsO6 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Li1+ is bonded to six equivalent O2- atoms to form LiO6 octahedra that share corners with six equivalent OsO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Li–O bond lengths are 2.19 Å. Ba2+ is bonded to twelve equivalent O2- atoms to form BaO12 cuboctahedra that share corners with twelve equivalent BaO12 cuboctahedra, faces with six equivalent BaO12 cuboctahedra, faces with four equivalent LiO6 octahedra, and faces with four equivalent OsO6 octahedra. All Ba–O bond lengths are 2.91 Å. Os7+ is bonded to six equivalent O2- atoms to form OsO6 octahedra that share corners with six equivalent LiO6 octahedra and faces with eight equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Os–O bond lengths are 1.91 Å. O2- is bonded in a distorted linear geometry to one Li1+, four equivalent Ba2+, and one Os7+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZrOs by Materials Project

OsZr is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Zr2+ is bonded in a body-centered cubic geometry to eight equivalent Os2- atoms. All Zr–Os bond lengths are 2.85 Å. Os2- is bonded in a body-centered cubic geometry to eight equivalent Zr2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaLa2OsO6 by Materials Project

NaLa2OsO6 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 34–39°. There are a spread of Na–O bond distances ranging from 2.32–2.38 Å. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.38–2.98 Å. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 34–39°. There is four shorter (1.99 Å) and two longer (2.00 Å) Os–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to one Na1+, three equivalent La3+, and one Os5+ atom. In the second O2- site, O2- is bonded to one Na1+, two equivalent La3+, and one Os5+ atom to form distorted corner-sharing ONaLa2Os tetrahedra. In the third O2- site, O2- is bonded in a 5-coordinate geometry to one Na1+, three equivalent La3+, and one Os5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiPr2OsO6 by Materials Project

LiPr2OsO6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 32–33°. There are two shorter (2.10 Å) and four longer (2.19 Å) Li–O bond lengths. Pr3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pr–O bond distances ranging from 2.39–2.77 Å. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 32–33°. There is four shorter (1.99 Å) and two longer (2.00 Å) Os–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent Pr3+, and one Os5+ atom. In the second O2- site, O2- is bonded to one Li1+, two equivalent Pr3+, and one Os5+ atom to form distorted corner-sharing OLiPr2Os tetrahedra. In the third O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent Pr3+, and one Os5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiNd2OsO6 by Materials Project

LiNd2OsO6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 33–34°. There are two shorter (2.09 Å) and four longer (2.19 Å) Li–O bond lengths. Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.36–2.76 Å. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 33–34°. There is four shorter (1.99 Å) and two longer (2.00 Å) Os–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent Nd3+, and one Os5+ atom. In the second O2- site, O2- is bonded to one Li1+, two equivalent Nd3+, and one Os5+ atom to form distorted corner-sharing OLiNd2Os trigonal pyramids. In the third O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent Nd3+, and one Os5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiLa2OsO6 by Materials Project

LiLa2OsO6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 30–31°. There are a spread of Li–O bond distances ranging from 2.11–2.19 Å. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.41–2.79 Å. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–31°. There is four shorter (1.99 Å) and two longer (2.00 Å) Os–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent La3+, and one Os5+ atom. In the second O2- site, O2- is bonded to one Li1+, two equivalent La3+, and one Os5+ atom to form distorted corner-sharing OLiLa2Os tetrahedra. In the third O2- site, O2- is bonded in a 5-coordinate geometry to one Li1+, three equivalent La3+, and one Os5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on VOs by Materials Project

VOs is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. V2+ is bonded in a body-centered cubic geometry to eight equivalent Os2- atoms. All V–Os bond lengths are 2.62 Å. Os2- is bonded in a body-centered cubic geometry to eight equivalent V2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Gd3OsO7 by Materials Project

Gd3OsO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded to seven O2- atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent OsO6 octahedra, corners with three equivalent GdO7 pentagonal bipyramids, edges with two equivalent OsO6 octahedra, and edges with two equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Gd–O bond distances ranging from 2.26–2.63 Å. In the second Gd3+ site, Gd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.35 Å) and four longer (2.69 Å) Gd–O bond lengths. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four equivalent GdO7 pentagonal bipyramids, and edges with four equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. There is two shorter (1.95 Å) and four longer (1.99 Å) Os–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+ and one Os5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Gd3+ and two equivalent Os5+ atoms. In the third O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of edge and corner-sharing OGd4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd3OsO7 by Materials Project

Nd3OsO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.40 Å) and four longer (2.75 Å) Nd–O bond lengths. In the second Nd3+ site, Nd3+ is bonded to seven O2- atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent OsO6 octahedra, corners with three equivalent NdO7 pentagonal bipyramids, edges with two equivalent OsO6 octahedra, and edges with two equivalent NdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 36°. There are a spread of Nd–O bond distances ranging from 2.31–2.60 Å. Os5+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four equivalent NdO7 pentagonal bipyramids, and edges with four equivalent NdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are four shorter (1.99 Å) and two longer (2.01 Å) Os–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Nd3+ and two equivalent Os5+ atoms. In the second O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Os5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2NiOsO6 by Materials Project

Sr2OsNiO6 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with twelve equivalent SrO12 cuboctahedra, faces with six equivalent SrO12 cuboctahedra, faces with four equivalent OsO6 octahedra, and faces with four equivalent NiO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.59–3.08 Å. Os6+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six equivalent NiO6 octahedra and faces with eight equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–20°. There is four shorter (1.94 Å) and two longer (1.95 Å) Os–O bond length. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent OsO6 octahedra and faces with eight equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–20°. There are four shorter (2.07 Å) and two longer (2.09 Å) Ni–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four equivalent Sr2+, one Os6+, and one Ni2+ atom. In the second O2- site, O2- is bonded to four equivalent Sr2+, one Os6+, and one Ni2+ atom to form a mixture of distorted corner and edge-sharing OSr4NiOs octahedra. The corner-sharing octahedra tilt angles range from 0–3°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na5OsO6 by Materials Project

Na5OsO6 is High Pressure (4-7GPa) Tellurium-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six NaO6 octahedra, edges with three equivalent OsO6 octahedra, and edges with nine NaO6 octahedra. The corner-sharing octahedra tilt angles range from 18–22°. There are a spread of Na–O bond distances ranging from 2.35–2.41 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four equivalent NaO6 octahedra, edges with two equivalent OsO6 octahedra, and edges with ten NaO6 octahedra. The corner-sharing octahedra tilt angles range from 1–22°. There are a spread of Na–O bond distances ranging from 2.35–2.61 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four equivalent NaO6 octahedra, edges with two equivalent OsO6 octahedra, and edges with ten NaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–18°. There are four shorter (2.31 Å) and two longer (2.80 Å) Na–O bond lengths. Os7+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six NaO6 octahedra and edges with twelve NaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There is two shorter (1.90 Å) and four longer (1.94 Å) Os–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Os7+ atom. In the second O2- site, O2- is bonded to five Na1+ and one Os7+ atom to form a mixture of distorted corner and edge-sharing ONa5Os octahedra. The corner-sharing octahedra tilt angles range from 0–17°.

36 MATERIALS SCIENCE↗