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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on K3Mn by Materials Project

K3Mn is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Mn atoms to form a mixture of distorted edge, corner, and face-sharing KK4Mn4 tetrahedra. All K–K bond lengths are 3.98 Å. All K–Mn bond lengths are 3.98 Å. In the second K site, K is bonded in a body-centered cubic geometry to eight equivalent K atoms. Mn is bonded in a body-centered cubic geometry to eight equivalent K atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Ru by Materials Project

K3Ru is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent K and four equivalent Ru atoms to form a mixture of distorted edge, corner, and face-sharing KK4Ru4 tetrahedra. All K–K bond lengths are 3.69 Å. All K–Ru bond lengths are 3.69 Å. In the second K site, K is bonded in a distorted body-centered cubic geometry to eight equivalent K and six equivalent Ru atoms. All K–Ru bond lengths are 4.26 Å. Ru is bonded in a body-centered cubic geometry to fourteen K atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KLi3 by Materials Project

KLi2Li is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four lithium molecules and one KLi2 framework. In the KLi2 framework, K is bonded in a body-centered cubic geometry to eight equivalent Li atoms. All K–Li bond lengths are 3.48 Å. Li is bonded to four equivalent K atoms to form a mixture of edge and corner-sharing LiK4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3BN2 by Materials Project

K3BN2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to four N3- atoms to form a mixture of distorted corner and edge-sharing KN4 tetrahedra. There are a spread of K–N bond distances ranging from 2.87–3.03 Å. In the second K1+ site, K1+ is bonded to four N3- atoms to form a mixture of distorted corner and edge-sharing KN4 tetrahedra. There are a spread of K–N bond distances ranging from 2.85–3.06 Å. In the third K1+ site, K1+ is bonded to four N3- atoms to form a mixture of corner and edge-sharing KN4 tetrahedra. There are a spread of K–N bond distances ranging from 2.75–2.87 Å. B3+ is bonded in a linear geometry to two N3- atoms. Both B–N bond lengths are 1.36 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted single-bond geometry to six K1+ and one B3+ atom. In the second N3- site, N3- is bonded in a distorted single-bond geometry to six K1+ and one B3+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1987

The thermal environment of transatmospheric vehicles

A transatmospheric vehicle using primarily air-breathing propulsion must fly in the denser part of the atmosphere to achieve adequate acceleration to reach orbital speed. The potentially long ascent times, combined with the need for a low-drag configuration, result in a severe aerothermodynamics environment. To achieve low drag, the vehicle must have a relatively sharp nose and wing leading edges. The ascent peak stagnation point and equilibrium wall temperatures for the wing leading edge can reach values of 4000 K and 3000 K, respectively, for high dynamic pressure trajectories, making some form of mass addition cooling mandatory. The corresponding temperatures during entry are about 1500 K lower. The vehicle windward centerline temperatures are more moderate, however, with values peaking around 1500 K. Therefore, radiative cooling should be effective over large areas of the vehicle. The windward, centerline heat loads are relatively insensitive to the dynamic pressure of the ascent trajectory, in contrast to the stagnation point and wing leading edge. The windward surface entry heat loads are much lower, but depend strongly on the flightpath.

Tauber, Michael E.↗
DOE OSTI2020

Materials Data on CsK3 by Materials Project

CsK3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Cs is bonded to twelve K atoms to form a mixture of edge, corner, and face-sharing CsK12 cuboctahedra. There are four shorter (4.78 Å) and eight longer (4.96 Å) Cs–K bond lengths. There are two inequivalent K sites. In the first K site, K is bonded in a 8-coordinate geometry to four equivalent Cs and four equivalent K atoms. All K–K bond lengths are 4.78 Å. In the second K site, K is bonded in a square co-planar geometry to four equivalent Cs atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KMnAg3(CN)6 by Materials Project

KMnAg3(CN)6 crystallizes in the trigonal P312 space group. The structure is three-dimensional. K1+ is bonded to six equivalent N3- atoms to form distorted KN6 octahedra that share edges with three equivalent MnN6 octahedra. All K–N bond lengths are 2.94 Å. Mn2+ is bonded to six equivalent N3- atoms to form MnN6 octahedra that share edges with three equivalent KN6 octahedra. All Mn–N bond lengths are 2.23 Å. Ag1+ is bonded in a linear geometry to two equivalent C2+ atoms. Both Ag–C bond lengths are 2.06 Å. C2+ is bonded in a linear geometry to one Ag1+ and one N3- atom. The C–N bond length is 1.17 Å. N3- is bonded in a 3-coordinate geometry to one K1+, one Mn2+, and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3B3O10 by Materials Project

K3B3O10 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are three inequivalent K sites. In the first K site, K is bonded in a 12-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.64–3.08 Å. In the second K site, K is bonded to eight O atoms to form distorted KO8 hexagonal bipyramids that share corners with two BO4 tetrahedra, edges with four KO8 hexagonal bipyramids, and edges with two BO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.70–3.23 Å. In the third K site, K is bonded to eight O atoms to form distorted KO8 hexagonal bipyramids that share corners with two BO4 tetrahedra, edges with four KO8 hexagonal bipyramids, and edges with two BO4 tetrahedra. There are a spread of K–O bond distances ranging from 2.71–3.24 Å. There are three inequivalent B sites. In the first B site, B is bonded to four O atoms to form BO4 tetrahedra that share corners with two KO8 hexagonal bipyramids, a cornercorner with one BO4 tetrahedra, and edges with two KO8 hexagonal bipyramids. There are a spread of B–O bond distances ranging from 1.44–1.48 Å. In the second B site, B is bonded to four O atoms to form BO4 tetrahedra that share corners with two KO8 hexagonal bipyramids, a cornercorner with one BO4 tetrahedra, and edges with two KO8 hexagonal bipyramids. There are a spread of B–O bond distances ranging from 1.43–1.48 Å. In the third B site, B is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.37 Å) and two longer (1.40 Å) B–O bond length. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to three K and one B atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two B atoms. In the third O site, O is bonded in a distorted single-bond geometry to three K and one B atom. In the fourth O site, O is bonded in a distorted single-bond geometry to three K and one B atom. In the fifth O site, O is bonded in a distorted T-shaped geometry to three K atoms. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to two K and two B atoms. In the seventh O site, O is bonded in a distorted single-bond geometry to two equivalent K and one B atom. In the eighth O site, O is bonded in a distorted bent 120 degrees geometry to two K and two B atoms. In the ninth O site, O is bonded in a distorted T-shaped geometry to three K atoms. In the tenth O site, O is bonded in a distorted single-bond geometry to three K and one B atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2FeCl5O by Materials Project

K2FeOCl5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K is bonded in a 10-coordinate geometry to ten Cl atoms. There are a spread of K–Cl bond distances ranging from 3.29–3.62 Å. Fe is bonded in a distorted octahedral geometry to one O and five Cl atoms. The Fe–O bond length is 1.78 Å. There are a spread of Fe–Cl bond distances ranging from 2.30–2.44 Å. O is bonded in a single-bond geometry to one Fe atom. There are four inequivalent Cl sites. In the first Cl site, Cl is bonded to four equivalent K and one Fe atom to form a mixture of face, edge, and corner-sharing ClK4Fe square pyramids. In the second Cl site, Cl is bonded to four equivalent K and one Fe atom to form a mixture of distorted face, edge, and corner-sharing ClK4Fe square pyramids. In the third Cl site, Cl is bonded to four equivalent K and one Fe atom to form a mixture of distorted face, edge, and corner-sharing ClK4Fe square pyramids. In the fourth Cl site, Cl is bonded in a distorted single-bond geometry to four equivalent K and one Fe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KNa(BH4)2 by Materials Project

NaK(BH4)2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent H+0.50+ atoms to form KH12 cuboctahedra that share edges with six equivalent KH12 cuboctahedra, edges with six equivalent NaH12 cuboctahedra, and edges with six equivalent BH4 tetrahedra. All K–H bond lengths are 2.79 Å. Na1+ is bonded to twelve H+0.50+ atoms to form distorted NaH12 cuboctahedra that share edges with six equivalent KH12 cuboctahedra, edges with six equivalent NaH12 cuboctahedra, and edges with six equivalent BH4 tetrahedra. There are six shorter (2.44 Å) and six longer (2.67 Å) Na–H bond lengths. B3- is bonded to four H+0.50+ atoms to form BH4 tetrahedra that share edges with three equivalent KH12 cuboctahedra and edges with three equivalent NaH12 cuboctahedra. There is one shorter (1.22 Å) and three longer (1.23 Å) B–H bond length. There are two inequivalent H+0.50+ sites. In the first H+0.50+ site, H+0.50+ is bonded in a single-bond geometry to three equivalent Na1+ and one B3- atom. In the second H+0.50+ site, H+0.50+ is bonded in a distorted single-bond geometry to two equivalent K1+, one Na1+, and one B3- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Tc by Materials Project

K3Tc is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to four equivalent Tc3- atoms to form a mixture of distorted edge and corner-sharing KTc4 tetrahedra. All K–Tc bond lengths are 3.96 Å. In the second K1+ site, K1+ is bonded in a square co-planar geometry to four equivalent Tc3- atoms. All K–Tc bond lengths are 4.07 Å. Tc3- is bonded to twelve K1+ atoms to form a mixture of face, edge, and corner-sharing TcK12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2024

The Early Data Release of the Dark Energy Spectroscopic Instrument

The Dark Energy Spectroscopic Instrument (DESI) completed its 5 month Survey Validation in 2021 May. Spectra of stellar and extragalactic targets from Survey Validation constitute the first major data sample from the DESI survey. This paper describes the public release of those spectra, the catalogs of derived properties, and the intermediate data products. In total, the public release includes good-quality spectral information from 466,447 objects targeted as part of the Milky Way Survey, 428,758 as part of the Bright Galaxy Survey, 227,318 as part of the Luminous Red Galaxy sample, 437,664 as part of the Emission Line Galaxy sample, and 76,079 as part of the Quasar sample. In addition, the release includes spectral information from 137,148 objects that expand the scope beyond the primary samples as part of a series of secondary programs. Here, we describe the spectral data, data quality, data products, Large-Scale Structure science catalogs, access to the data, and references that provide relevant background to using these spectra.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Materials Data on KLa(CuO2)2 by Materials Project

KLa(CuO2)2 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. K1+ is bonded to eight equivalent O2- atoms to form distorted edge-sharing KO8 hexagonal bipyramids. All K–O bond lengths are 2.88 Å. La3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All La–O bond lengths are 2.52 Å. Cu2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.98 Å. O2- is bonded to two equivalent K1+, two equivalent La3+, and two equivalent Cu2+ atoms to form a mixture of distorted edge, face, and corner-sharing OK2La2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KMg3(SiO3)4 by Materials Project

KMg3(SiO3)4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. K is bonded to twelve O atoms to form KO12 cuboctahedra that share edges with six equivalent KO12 cuboctahedra and edges with twelve SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 3.05–3.16 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.98–2.17 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with six equivalent MgO6 octahedra. There are two shorter (2.06 Å) and four longer (2.12 Å) Mg–O bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two equivalent Si atoms. In the third O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two equivalent Si atoms. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent K and two equivalent Si atoms. In the fifth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Mg atoms. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent K and two equivalent Si atoms. In the seventh O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the eighth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KMg3(SiO3)4 by Materials Project

KMg3(SiO3)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K is bonded to twelve O atoms to form KO12 cuboctahedra that share edges with six equivalent KO12 cuboctahedra and edges with twelve SiO4 tetrahedra. There are a spread of K–O bond distances ranging from 3.15–3.22 Å. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with six MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.98–2.14 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with six equivalent MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.12 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 54–59°. There is one shorter (1.61 Å) and three longer (1.66 Å) Si–O bond length. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra, corners with three equivalent SiO4 tetrahedra, and edges with three equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 56–59°. There is one shorter (1.61 Å) and three longer (1.66 Å) Si–O bond length. There are six inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to two equivalent K and two Si atoms. In the third O site, O is bonded in a rectangular see-saw-like geometry to three Mg and one Si atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two Si atoms. In the fifth O site, O is bonded in a distorted trigonal non-coplanar geometry to three Mg atoms. In the sixth O site, O is bonded in a distorted bent 120 degrees geometry to two equivalent K and two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(WO3)6 by Materials Project

K(WO3)6 crystallizes in the trigonal P-31m space group. The structure is three-dimensional. K1+ is bonded to twelve equivalent O2- atoms to form KO12 cuboctahedra that share edges with twelve equivalent WO6 octahedra. All K–O bond lengths are 3.36 Å. W+5.83+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six equivalent WO6 octahedra and edges with two equivalent KO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+5.83+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.83+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two equivalent W+5.83+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Effect of rare earth size on network structure and glass forming ability in binary aluminum garnets

Rare earth aluminate glasses are potentially useful for optical, luminescence, and laser applications. As reluctant glass formers, these materials exhibit unconventional atomic structures. To better understand how their structures correlate with glass formation, we investigate two rare earth aluminum garnet melts, La 3 Al 5 O 12 (LAG) and Yb 3 Al 5 O 12 (YbAG), which represent the relative extremes of good and poor glass forming ability in rare earth aluminates. Structural models have been refined to high-energy X-ray diffraction data over 1340–2740 K. Both melts contain mixtures of AlO 4 , AlO 5 , and AlO 6 polyhedra, with larger fractions of [5] Al and [6] Al in YbAG. Extrapolation of the Al–O coordination distributions to the glass transition match closely with 27 Al nuclear magnetic resonance measurements of (La 1−z Y z ) 3 Al 5 O 12 glasses, z = 0 to 1. During cooling, the mean coordination numbers increase for La–O in LAG from 6.45(8) to 6.98(8) and for Yb–O in YbAG from 6.02(8) to 6.21(8). Linkedness among Al–O polyhedra at ∼2450 K is mostly corner-sharing, with 9% edge-sharing in LAG and 19% in YbAG. Among [4] Al units, both melts have 6% edge-sharing that convert to all corner-sharing upon cooling. Network connectivity is compared using a newly defined metric, K n , that is similar to the Q n distribution but that accounts for the edge-sharing and triply bonded oxygen present in these melts. The lower glass forming ability in YbAG as compared to LAG correlates with more edge-sharing, associated with the larger fractions of [5] Al and [6] Al, and lower connectivity among [4] Al units.

Wilke, Stephen K. [Materials Development, Inc., Ar↗
DOE OSTI2020

Materials Data on KSn2 by Materials Project

KSn2 is Hexagonal Laves structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K is bonded in a 12-coordinate geometry to four equivalent K and twelve Sn atoms. There are a spread of K–K bond distances ranging from 3.63–4.08 Å. There are a spread of K–Sn bond distances ranging from 3.65–3.92 Å. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded to six equivalent K and six Sn atoms to form a mixture of edge, corner, and face-sharing SnK6Sn6 cuboctahedra. All Sn–Sn bond lengths are 3.16 Å. In the second Sn site, Sn is bonded to six equivalent K and six Sn atoms to form a mixture of distorted edge, corner, and face-sharing SnK6Sn6 cuboctahedra. There are a spread of Sn–Sn bond distances ranging from 3.27–3.42 Å. In the third Sn site, Sn is bonded to six equivalent K and six Sn atoms to form a mixture of distorted edge, corner, and face-sharing SnK6Sn6 cuboctahedra.

36 MATERIALS SCIENCE↗