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All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

Observed and Modeled Trends in Southern Ocean Sea Ice

Conceptual models and global climate model (GCM) simulations have both indicated the likelihood of an enhanced sensitivity to climate change in the polar regions, derived from the positive feedbacks brought about by the polar abundance of snow and ice surfaces. Some models further indicate that the changes in the polar regions can have a significant impact globally. For instance, 37% of the temperature sensitivity to a doubling of atmospheric CO2 in simulations with the GCM of the Goddard Institute for Space Studies (GISS) is attributable exclusively to inclusion of sea ice variations in the model calculations. Both sea ice thickness and sea ice extent decrease markedly in the doubled CO, case, thereby allowing the ice feedbacks to occur. Stand-alone sea ice models have shown Southern Ocean hemispherically averaged winter ice-edge retreats of 1.4 deg latitude for each 1 K increase in atmospheric temperatures. Observations, however, show a much more varied Southern Ocean ice cover, both spatially and temporally, than many of the modeled expectations. In fact, the satellite passive-microwave record of Southern Ocean sea ice since late 1978 has revealed overall increases rather than decreases in ice extents, with ice extent trends on the order of 11,000 sq km/year. When broken down spatially, the positive trends are strongest in the Ross Sea, while the trends are negative in the Bellingshausen/Amundsen Seas. Greater spatial detail can be obtained by examining trends in the length of the sea ice season, and those trends show a coherent picture of shortening sea ice seasons throughout almost the entire Bellingshausen and Amundsen Seas to the west of the Antarctic Peninsula and in the far western Weddell Sea immediately to the east of the Peninsula, with lengthening sea ice seasons around much of the rest of the continent. This pattern corresponds well with the spatial pattern of temperature trends, as the Peninsula region is the one region in the Antarctic with a strong record of temperature increases. Still, although the patterns of the temperature and ice changes match fairly well, there is a substantial ways to go before these patterns are understood (and can be modeled) in the full context of global change.

Parkinson, Claire L.↗
NASA NTRS2017

Habitable Moist Atmospheres on Terrestrial Planets near the Inner Edge of the Habitable Zone Around M Dwarfs

Terrestrial planets in the habitable zones (HZs) of low-mass stars and cool dwarfs have received significant scrutiny recently. Transit spectroscopy of such planets with the James Webb Space Telescope (JWST) represents our best shot at obtaining the spectrum of a habitable planet within the next decade. As these planets are likely tidally locked, improved 3D numerical simulations of such planetary atmospheres are needed to guide target selection. Here we use a 3D climate system model, updated with new water-vapor absorption coefficients derived from the HITRAN 2012 database, to study ocean-covered planets at the inner edge of the HZ around late M to mid- K stars (2600 K less than or equal to T(sub eff) less than or equal to 4500 K). Our results indicate that these updated water-vapor coefficients result in significant warming compared to previous studies, so the inner HZ around M dwarfs is not as close as suggested by earlier work. Assuming synchronously rotating Earth-sized and Earth-mass planets with background 1 bar N2 atmospheres, we find that planets at the inner HZ of stars with T(sub eff) greater than 3000 K undergo the classical ''moist greenhouse'' (H2O mixing ratio greater than 10(exp -3) in the stratosphere) at significantly lower surface temperature (approx. 280 K) in our 3D model compared with 1D climate models (approx. 340 K). This implies that some planets around low-mass stars can simultaneously undergo water loss and remain habitable. However, for stars with T(sub eff) less than or equal to 3000 K, planets at the inner HZ may directly transition to a runaway state, while bypassing the moist greenhouse water loss entirely. We analyze transmission spectra of planets in a moist greenhouse regime and find that there are several prominent H2O features, including a broad feature between 5 and 8 micron, within JWST MIRI instrument range. Thus, relying only on standard Earth-analog spectra with 24 hr rotation period around M dwarfs for habitability studies will miss the strong H2O features that one would expect to see on synchronously rotating planets around M dwarf stars, with JWST.

Kopparapu, Ravi kumar↗
DOE OSTI2021

Tapered structure construction

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

Smith, Eric D.↗
DOE OSTI2023

Tapered structure construction

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

Smith, Eric D.↗
DOE OSTI2020

Materials Data on K3Ba by Materials Project

K3Ba crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight K and four equivalent Ba atoms to form distorted KK8Ba4 cuboctahedra that share corners with twelve equivalent KK8Ba4 cuboctahedra, edges with eight equivalent KK8Ba4 cuboctahedra, edges with eight equivalent BaK12 cuboctahedra, faces with four equivalent BaK12 cuboctahedra, and faces with ten equivalent KK8Ba4 cuboctahedra. There are four shorter (4.44 Å) and four longer (4.77 Å) K–K bond lengths. All K–Ba bond lengths are 4.77 Å. In the second K site, K is bonded in a square co-planar geometry to eight equivalent K and four equivalent Ba atoms. All K–Ba bond lengths are 4.44 Å. Ba is bonded to twelve K atoms to form BaK12 cuboctahedra that share corners with four equivalent BaK12 cuboctahedra, edges with eight equivalent BaK12 cuboctahedra, edges with sixteen equivalent KK8Ba4 cuboctahedra, faces with four equivalent BaK12 cuboctahedra, and faces with eight equivalent KK8Ba4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Magnetic order of tetragonal CuO ultrathin films

Here, we present a detailed low-energy muon spin rotation and x-ray magnetic circular dichroism (XMCD) investigation of the magnetic structure in ultrathin tetragonal (T)-CuO films. The measured muon-spin polarization decay indicates an antiferromagnetic (AFM) order with a transition temperature higher than 200 K. The XMCD signal obtained around the CuL 2,3 edges indicates the presence of pinned Cu 2+ moments that are parallel to the sample surface, and additionally, isotropic paramagnetic moments. The pinning of some of the Cu moments is caused by an AFM ordering consisting of moments that lie most likely in plane of the film. Moreover, pinned moments show a larger orbital magnetic moment contribution with an approximate ratio of m orb /m spin =1.5, indicating that these spins are located at sites with reduced symmetry. Some fractions of the pinned moments remain pinned from an AFM background even at 360 K, indicating that T N >360K. We propose a simple model that explains these experimental findings, showing that the magnetic order of the T-CuO ultrathin films differs from the theoretical predictions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2020

Materials Data on KMg14BO15 by Materials Project

KMg14BO15 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. K is bonded to six O atoms to form distorted KO6 octahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of K–O bond distances ranging from 2.24–2.73 Å. There are ten inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent KO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Mg–O bond distances ranging from 2.00–2.24 Å. In the second Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, corners with two equivalent MgO5 trigonal bipyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of Mg–O bond distances ranging from 1.98–2.24 Å. In the third Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent KO6 octahedra, edges with five MgO6 octahedra, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 1–30°. There are a spread of Mg–O bond distances ranging from 1.97–2.32 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with seven MgO6 octahedra, edges with two equivalent MgO5 square pyramids, and edges with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.04–2.29 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with two equivalent KO6 octahedra, edges with six MgO6 octahedra, and edges with four equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 0–9°. There are a spread of Mg–O bond distances ranging from 2.05–2.24 Å. In the sixth Mg site, Mg is bonded in a square co-planar geometry to four O atoms. There are a spread of Mg–O bond distances ranging from 2.05–2.15 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with two equivalent KO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are a spread of Mg–O bond distances ranging from 2.06–2.29 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–17°. There are a spread of Mg–O bond distances ranging from 2.05–2.45 Å. In the ninth Mg site, Mg is bonded to five O atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent MgO6 octahedra, a cornercorner with one MgO5 square pyramid, corners with three equivalent MgO5 trigonal bipyramids, an edgeedge with one KO6 octahedra, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–31°. There are a spread of Mg–O bond distances ranging from 2.05–2.24 Å. In the tenth Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with four equivalent MgO6 octahedra, corners with two equivalent MgO5 trigonal bipyramids, an edgeedge with one KO6 octahedra, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 5–9°. There are a spread of Mg–O bond distances ranging from 1.99–2.56 Å. B is bonded in a bent 150 degrees geometry to two equivalent O atoms. Both B–O bond lengths are 1.45 Å. There are eleven inequivalent O sites. In the first O site, O is bonded to one K and five Mg atoms to form OKMg5 octahedra that share corners with four OKMg5 octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. In the second O site, O is bonded to one K and five Mg atoms to form OKMg5 octahedra that share corners with four OKMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the third O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with two equivalent OKMg5 octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 6°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with seven OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. In the fifth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with seven OKMg5 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–9°. In the sixth O site, O is bonded to two equivalent K and four Mg atoms to form OK2Mg4 octahedra that share corners with four OMg6 octahedra and edges with eight OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the seventh O site, O is bonded in a square co-planar geometry to four Mg atoms. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra and edges with twelve OKMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with eight OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–7°. In the tenth O site, O is bonded in a 1-coordinate geometry to one K, four Mg, and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four equivalent OMg6 octahedra, edges with ten OKMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 2–6°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2NdF5 by Materials Project

K2NdF5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.71–2.94 Å. Nd3+ is bonded to seven F1- atoms to form distorted edge-sharing NdF7 pentagonal bipyramids. There are a spread of Nd–F bond distances ranging from 2.29–2.38 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Nd3+ atom. In the second F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Nd3+ atom. In the third F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Nd3+ atom. In the fourth F1- site, F1- is bonded to two equivalent K1+ and two equivalent Nd3+ atoms to form a mixture of distorted corner and edge-sharing FK2Nd2 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2NdCl5 by Materials Project

K2NdCl5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of K–Cl bond distances ranging from 3.21–3.46 Å. Nd3+ is bonded to seven Cl1- atoms to form distorted edge-sharing NdCl7 pentagonal bipyramids. There are a spread of Nd–Cl bond distances ranging from 2.79–2.87 Å. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to four equivalent K1+ and one Nd3+ atom to form distorted ClK4Nd trigonal bipyramids that share corners with four equivalent ClK2Nd2 tetrahedra, corners with eight ClK4Nd trigonal bipyramids, edges with four equivalent ClK2Nd2 tetrahedra, an edgeedge with one ClK4Nd trigonal bipyramid, and a faceface with one ClK4Nd trigonal bipyramid. In the second Cl1- site, Cl1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Nd3+ atom. In the third Cl1- site, Cl1- is bonded to four equivalent K1+ and one Nd3+ atom to form distorted ClK4Nd trigonal bipyramids that share corners with eight equivalent ClK2Nd2 tetrahedra, corners with four equivalent ClK4Nd trigonal bipyramids, edges with two equivalent ClK2Nd2 tetrahedra, edges with three ClK4Nd trigonal bipyramids, and a faceface with one ClK4Nd trigonal bipyramid. In the fourth Cl1- site, Cl1- is bonded to two equivalent K1+ and two equivalent Nd3+ atoms to form distorted ClK2Nd2 tetrahedra that share corners with six equivalent ClK2Nd2 tetrahedra, corners with six ClK4Nd trigonal bipyramids, an edgeedge with one ClK2Nd2 tetrahedra, and edges with three ClK4Nd trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KClO3 by Materials Project

KClO3 is Potassium chlorate structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. K is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 2.86–3.18 Å. There are two inequivalent O sites. In the first O site, O is bonded in a 4-coordinate geometry to three equivalent K and one Cl atom. The O–Cl bond length is 1.51 Å. In the second O site, O is bonded to three equivalent K and one Cl atom to form a mixture of distorted edge and corner-sharing OK3Cl tetrahedra. The O–Cl bond length is 1.51 Å. Cl is bonded in a trigonal non-coplanar geometry to three O atoms.

36 MATERIALS SCIENCE↗
NASA NTRS1997

Aerothermal Performance Constraints for Hypervelocity Small Radius Unswept Leading Edges and Nosetips

Small radius leading edges and nosetips were utilized to minimize wave drag in early hypervelocity vehicle concepts until further analysis demonstrated that extreme aerothermodynamic heating would cause severe ablation or blunting of the available thermal protection system materials. Recent studies indicate that ultrahigh temperature ceramic (UHTC) materials are shape stable at temperatures approaching 3033 K and will be available for use as sharp UHTC leading edge components in the near future. Aerothermal performance constraints for sharp components made from these materials are presented in this work to demonstrate the effects of convective blocking, surface catalycity, surface emissivity, and rarefied flow effects on steady state operation at altitudes from sea level to 90 km. These components are capable of steady state operation at velocities up to 7.9 km/s at attitudes near 90 km.

Kolodziej, Paul↗
DOE OSTI2020

Materials Data on K3Y by Materials Project

K3Y is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight K and four equivalent Y atoms to form distorted KK8Y4 cuboctahedra that share corners with twelve equivalent KK8Y4 cuboctahedra, edges with eight equivalent KK8Y4 cuboctahedra, edges with eight equivalent YK12 cuboctahedra, faces with four equivalent YK12 cuboctahedra, and faces with ten equivalent KK8Y4 cuboctahedra. There are four shorter (4.18 Å) and four longer (4.38 Å) K–K bond lengths. All K–Y bond lengths are 4.38 Å. In the second K site, K is bonded in a distorted square co-planar geometry to eight equivalent K and four equivalent Y atoms. All K–Y bond lengths are 4.18 Å. Y is bonded to twelve K atoms to form YK12 cuboctahedra that share corners with four equivalent YK12 cuboctahedra, edges with eight equivalent YK12 cuboctahedra, edges with sixteen equivalent KK8Y4 cuboctahedra, faces with four equivalent YK12 cuboctahedra, and faces with eight equivalent KK8Y4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Th by Materials Project

K3Th is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight K and four equivalent Th atoms to form distorted KK8Th4 cuboctahedra that share corners with twelve equivalent KK8Th4 cuboctahedra, edges with eight equivalent KK8Th4 cuboctahedra, edges with eight equivalent ThK12 cuboctahedra, faces with four equivalent ThK12 cuboctahedra, and faces with ten equivalent KK8Th4 cuboctahedra. There are four shorter (3.98 Å) and four longer (4.36 Å) K–K bond lengths. All K–Th bond lengths are 4.36 Å. In the second K site, K is bonded in a square co-planar geometry to eight equivalent K and four equivalent Th atoms. All K–Th bond lengths are 3.98 Å. Th is bonded to twelve K atoms to form ThK12 cuboctahedra that share corners with four equivalent ThK12 cuboctahedra, edges with eight equivalent ThK12 cuboctahedra, edges with sixteen equivalent KK8Th4 cuboctahedra, faces with four equivalent ThK12 cuboctahedra, and faces with eight equivalent KK8Th4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Zr by Materials Project

K3Zr is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to eight K and four equivalent Zr atoms to form distorted KK8Zr4 cuboctahedra that share corners with twelve equivalent KK8Zr4 cuboctahedra, edges with eight equivalent KK8Zr4 cuboctahedra, edges with eight equivalent ZrK12 cuboctahedra, faces with four equivalent ZrK12 cuboctahedra, and faces with ten equivalent KK8Zr4 cuboctahedra. There are four shorter (4.08 Å) and four longer (4.24 Å) K–K bond lengths. All K–Zr bond lengths are 4.24 Å. In the second K site, K is bonded in a distorted square co-planar geometry to eight equivalent K and four equivalent Zr atoms. All K–Zr bond lengths are 4.08 Å. Zr is bonded to twelve K atoms to form ZrK12 cuboctahedra that share corners with four equivalent ZrK12 cuboctahedra, edges with eight equivalent ZrK12 cuboctahedra, edges with sixteen equivalent KK8Zr4 cuboctahedra, faces with four equivalent ZrK12 cuboctahedra, and faces with eight equivalent KK8Zr4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Ga2As3 by Materials Project

K2Ga2As3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six As+2.67- atoms to form distorted KAs6 octahedra that share corners with eight GaAs4 tetrahedra, an edgeedge with one KAs6 octahedra, and edges with four GaAs4 tetrahedra. There are a spread of K–As bond distances ranging from 3.31–3.71 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six As+2.67- atoms. There are a spread of K–As bond distances ranging from 3.28–3.81 Å. In the third K1+ site, K1+ is bonded in a 5-coordinate geometry to five As+2.67- atoms. There are a spread of K–As bond distances ranging from 3.40–3.63 Å. In the fourth K1+ site, K1+ is bonded in a 2-coordinate geometry to six As+2.67- atoms. There are a spread of K–As bond distances ranging from 3.19–3.89 Å. There are four inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four As+2.67- atoms to form GaAs4 tetrahedra that share a cornercorner with one KAs6 octahedra, corners with five GaAs4 tetrahedra, an edgeedge with one KAs6 octahedra, and an edgeedge with one GaAs4 tetrahedra. The corner-sharing octahedral tilt angles are 17°. There are a spread of Ga–As bond distances ranging from 2.49–2.65 Å. In the second Ga3+ site, Ga3+ is bonded to four As+2.67- atoms to form GaAs4 tetrahedra that share corners with two equivalent KAs6 octahedra, corners with five GaAs4 tetrahedra, edges with two equivalent KAs6 octahedra, and an edgeedge with one GaAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–63°. There are a spread of Ga–As bond distances ranging from 2.53–2.55 Å. In the third Ga3+ site, Ga3+ is bonded to four As+2.67- atoms to form GaAs4 tetrahedra that share corners with three equivalent KAs6 octahedra, corners with five GaAs4 tetrahedra, an edgeedge with one KAs6 octahedra, and an edgeedge with one GaAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 1–55°. There are a spread of Ga–As bond distances ranging from 2.49–2.56 Å. In the fourth Ga3+ site, Ga3+ is bonded to four As+2.67- atoms to form GaAs4 tetrahedra that share corners with two equivalent KAs6 octahedra, corners with five GaAs4 tetrahedra, and an edgeedge with one GaAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–29°. There are a spread of Ga–As bond distances ranging from 2.55–2.60 Å. There are six inequivalent As+2.67- sites. In the first As+2.67- site, As+2.67- is bonded in a 3-coordinate geometry to three K1+ and three Ga3+ atoms. In the second As+2.67- site, As+2.67- is bonded to four K1+ and three Ga3+ atoms to form distorted edge-sharing AsK4Ga3 pentagonal bipyramids. In the third As+2.67- site, As+2.67- is bonded in a 6-coordinate geometry to three K1+ and three Ga3+ atoms. In the fourth As+2.67- site, As+2.67- is bonded in a 7-coordinate geometry to four K1+, two Ga3+, and one As+2.67- atom. The As–As bond length is 2.51 Å. In the fifth As+2.67- site, As+2.67- is bonded in a 3-coordinate geometry to five K1+ and three Ga3+ atoms. In the sixth As+2.67- site, As+2.67- is bonded in a 7-coordinate geometry to four K1+, two Ga3+, and one As+2.67- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Bi3F11 by Materials Project

K2Bi3F11 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to five F1- atoms to form distorted KF5 trigonal bipyramids that share corners with three equivalent KF7 hexagonal pyramids and corners with six equivalent KF5 trigonal bipyramids. There are a spread of K–F bond distances ranging from 2.47–2.77 Å. In the second K1+ site, K1+ is bonded to seven F1- atoms to form distorted KF7 hexagonal pyramids that share corners with three equivalent KF5 trigonal bipyramids and edges with six equivalent KF7 hexagonal pyramids. There are a spread of K–F bond distances ranging from 2.77–2.91 Å. There are three inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Bi–F bond distances ranging from 2.21–2.68 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of Bi–F bond distances ranging from 2.14–2.79 Å. In the third Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Bi–F bond distances ranging from 2.18–2.61 Å. There are eleven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to one K1+ and two equivalent Bi3+ atoms. In the second F1- site, F1- is bonded to three equivalent K1+ and one Bi3+ atom to form distorted FK3Bi tetrahedra that share corners with six equivalent FK3Bi tetrahedra and corners with three equivalent FK4 trigonal pyramids. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Bi3+ atoms. In the fourth F1- site, F1- is bonded to four K1+ atoms to form FK4 trigonal pyramids that share corners with three equivalent FK3Bi tetrahedra and corners with six equivalent FK4 trigonal pyramids. In the fifth F1- site, F1- is bonded in a 4-coordinate geometry to three equivalent K1+ and one Bi3+ atom. In the sixth F1- site, F1- is bonded in a 1-coordinate geometry to three Bi3+ atoms. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to one K1+ and two equivalent Bi3+ atoms. In the eighth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Bi3+ atoms. In the ninth F1- site, F1- is bonded in a 1-coordinate geometry to three Bi3+ atoms. In the tenth F1- site, F1- is bonded in a bent 120 degrees geometry to two Bi3+ atoms. In the eleventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K3Mo by Materials Project

K3Mo is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 4-coordinate geometry to four equivalent K and four equivalent Mo atoms. All K–K bond lengths are 4.04 Å. All K–Mo bond lengths are 4.04 Å. In the second K site, K is bonded to eight equivalent K and four equivalent Mo atoms to form KK8Mo4 cuboctahedra that share corners with four equivalent KK8Mo4 cuboctahedra, corners with eight equivalent MoK12 cuboctahedra, edges with eight equivalent KK8Mo4 cuboctahedra, faces with four equivalent KK8Mo4 cuboctahedra, and faces with six equivalent MoK12 cuboctahedra. All K–Mo bond lengths are 4.27 Å. Mo is bonded to twelve K atoms to form distorted MoK12 cuboctahedra that share corners with four equivalent MoK12 cuboctahedra, corners with eight equivalent KK8Mo4 cuboctahedra, edges with eight equivalent MoK12 cuboctahedra, faces with four equivalent MoK12 cuboctahedra, and faces with six equivalent KK8Mo4 cuboctahedra.

36 MATERIALS SCIENCE↗