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DOE OSTI2020

Materials Data on PrGa4Os by Materials Project

PrOsGa4 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent Pr sites. In the first Pr site, Pr is bonded in a 12-coordinate geometry to four equivalent Os and twelve Ga atoms. All Pr–Os bond lengths are 3.53 Å. There are a spread of Pr–Ga bond distances ranging from 3.05–3.47 Å. In the second Pr site, Pr is bonded in a 10-coordinate geometry to twelve Ga atoms. There are a spread of Pr–Ga bond distances ranging from 3.08–3.53 Å. There are two inequivalent Os sites. In the first Os site, Os is bonded in a 8-coordinate geometry to eight Ga atoms. There are a spread of Os–Ga bond distances ranging from 2.61–2.67 Å. In the second Os site, Os is bonded in a 8-coordinate geometry to two equivalent Pr and eight Ga atoms. There are a spread of Os–Ga bond distances ranging from 2.59–2.68 Å. There are six inequivalent Ga sites. In the first Ga site, Ga is bonded in a 2-coordinate geometry to three Pr, two Os, and four Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.73–2.81 Å. In the second Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent Pr, two equivalent Os, and six Ga atoms. Both Ga–Ga bond lengths are 2.85 Å. In the third Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent Pr, three Os, and five Ga atoms. There are one shorter (2.77 Å) and two longer (2.82 Å) Ga–Ga bond lengths. In the fourth Ga site, Ga is bonded in a 10-coordinate geometry to two Pr, two equivalent Os, and six Ga atoms. The Ga–Ga bond length is 2.77 Å. In the fifth Ga site, Ga is bonded in a 5-coordinate geometry to four Pr, two equivalent Os, and one Ga atom. The Ga–Ga bond length is 2.78 Å. In the sixth Ga site, Ga is bonded to six Pr and six Ga atoms to form face-sharing GaPr6Ga6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaGa4Os by Materials Project

LaOsGa4 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent La sites. In the first La site, La is bonded in a 12-coordinate geometry to four equivalent Os and twelve Ga atoms. All La–Os bond lengths are 3.54 Å. There are a spread of La–Ga bond distances ranging from 3.06–3.50 Å. In the second La site, La is bonded in a 10-coordinate geometry to twelve Ga atoms. There are a spread of La–Ga bond distances ranging from 3.10–3.54 Å. There are two inequivalent Os sites. In the first Os site, Os is bonded in a 8-coordinate geometry to eight Ga atoms. There are a spread of Os–Ga bond distances ranging from 2.62–2.69 Å. In the second Os site, Os is bonded in a 8-coordinate geometry to two equivalent La and eight Ga atoms. There are a spread of Os–Ga bond distances ranging from 2.60–2.69 Å. There are six inequivalent Ga sites. In the first Ga site, Ga is bonded in a 2-coordinate geometry to three La, two Os, and four Ga atoms. There are a spread of Ga–Ga bond distances ranging from 2.73–2.83 Å. In the second Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent La, two equivalent Os, and six Ga atoms. Both Ga–Ga bond lengths are 2.86 Å. In the third Ga site, Ga is bonded in a 10-coordinate geometry to two equivalent La, three Os, and five Ga atoms. There are one shorter (2.77 Å) and two longer (2.83 Å) Ga–Ga bond lengths. In the fourth Ga site, Ga is bonded in a 10-coordinate geometry to two La, two equivalent Os, and six Ga atoms. The Ga–Ga bond length is 2.78 Å. In the fifth Ga site, Ga is bonded in a 5-coordinate geometry to four La, two equivalent Os, and one Ga atom. The Ga–Ga bond length is 2.80 Å. In the sixth Ga site, Ga is bonded to six La and six Ga atoms to form face-sharing GaLa6Ga6 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb3Os2 by Materials Project

Nb3Os2 crystallizes in the orthorhombic Cmm2 space group. The structure is three-dimensional. there are seven inequivalent Nb sites. In the first Nb site, Nb is bonded in a 6-coordinate geometry to eight Nb and seven Os atoms. There are a spread of Nb–Nb bond distances ranging from 2.75–3.28 Å. There are a spread of Nb–Os bond distances ranging from 2.94–3.27 Å. In the second Nb site, Nb is bonded in a 1-coordinate geometry to three Nb and eight Os atoms. There are two shorter (2.76 Å) and one longer (2.88 Å) Nb–Nb bond lengths. There are a spread of Nb–Os bond distances ranging from 2.85–3.20 Å. In the third Nb site, Nb is bonded in a 4-coordinate geometry to two Nb and five Os atoms. The Nb–Nb bond length is 2.65 Å. There are a spread of Nb–Os bond distances ranging from 2.80–3.12 Å. In the fourth Nb site, Nb is bonded in a 4-coordinate geometry to two Nb and five Os atoms. The Nb–Nb bond length is 2.65 Å. There are a spread of Nb–Os bond distances ranging from 2.80–3.13 Å. In the fifth Nb site, Nb is bonded in a 7-coordinate geometry to four Nb and five Os atoms. Both Nb–Nb bond lengths are 2.55 Å. There are a spread of Nb–Os bond distances ranging from 2.85–2.92 Å. In the sixth Nb site, Nb is bonded in a 2-coordinate geometry to one Nb and seven Os atoms. There are a spread of Nb–Os bond distances ranging from 2.54–2.89 Å. In the seventh Nb site, Nb is bonded in a 7-coordinate geometry to four Nb and five Os atoms. There are a spread of Nb–Os bond distances ranging from 2.85–2.91 Å. There are five inequivalent Os sites. In the first Os site, Os is bonded to six Nb and six Os atoms to form distorted OsNb6Os6 cuboctahedra that share corners with sixteen OsNb9Os3 cuboctahedra, edges with two equivalent OsNb6Os6 cuboctahedra, and faces with four equivalent OsNb9Os3 cuboctahedra. There are four shorter (2.63 Å) and two longer (2.79 Å) Os–Os bond lengths. In the second Os site, Os is bonded to eight Nb and four equivalent Os atoms to form OsNb8Os4 cuboctahedra that share corners with sixteen OsNb9Os3 cuboctahedra, edges with two equivalent OsNb8Os4 cuboctahedra, and faces with four equivalent OsNb9Os3 cuboctahedra. All Os–Os bond lengths are 2.66 Å. In the third Os site, Os is bonded to nine Nb and three Os atoms to form distorted OsNb9Os3 cuboctahedra that share corners with eleven OsNb8Os4 cuboctahedra, edges with three equivalent OsNb9Os3 cuboctahedra, and faces with seven OsNb6Os6 cuboctahedra. There are one shorter (2.68 Å) and one longer (2.86 Å) Os–Os bond lengths. In the fourth Os site, Os is bonded to nine Nb and three Os atoms to form distorted OsNb9Os3 cuboctahedra that share corners with eleven OsNb6Os6 cuboctahedra, edges with three equivalent OsNb9Os3 cuboctahedra, and faces with seven OsNb8Os4 cuboctahedra. There are one shorter (2.63 Å) and one longer (2.84 Å) Os–Os bond lengths. In the fifth Os site, Os is bonded in a distorted linear geometry to nine Nb and five Os atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2Os(NO5)2 by Materials Project

K2Os(NO5)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.76–3.23 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.84–3.29 Å. Os8+ is bonded to four O2- atoms to form distorted edge-sharing OsO4 trigonal pyramids. There are a spread of Os–O bond distances ranging from 1.76–1.96 Å. There are two inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.26 Å) N–O bond length. In the second N5+ site, N5+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both N–O bond lengths are 1.25 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one N5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Os8+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one Os8+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two O2- atoms. Both O–O bond lengths are 1.32 Å. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to three K1+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two K1+ and one O2- atom. In the ninth O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent K1+ and one O2- atom. In the tenth O2- site, O2- is bonded in a water-like geometry to two equivalent Os8+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Os2Xe(O3F5)2 by Materials Project

XeF5Os2O6F5 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four Os2O6F5 clusters and four XeF5 clusters. In each Os2O6F5 cluster, Os is bonded to three O and three F atoms to form distorted corner-sharing OsO3F3 octahedra. The corner-sharing octahedral tilt angles are 24°. There is two shorter (1.71 Å) and one longer (1.72 Å) Os–O bond length. There are a spread of Os–F bond distances ranging from 2.00–2.17 Å. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Os atom. In the second O site, O is bonded in a single-bond geometry to one Os atom. In the third O site, O is bonded in a single-bond geometry to one Os atom. There are three inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to two equivalent Os atoms. In the second F site, F is bonded in a single-bond geometry to one Os atom. In the third F site, F is bonded in a single-bond geometry to one Os atom. In each XeF5 cluster, Xe is bonded in a distorted square pyramidal geometry to five F atoms. There is three shorter (1.98 Å) and two longer (1.99 Å) Xe–F bond length. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Xe atom. In the second F site, F is bonded in a single-bond geometry to one Xe atom. In the third F site, F is bonded in a single-bond geometry to one Xe atom. In the fourth F site, F is bonded in a single-bond geometry to one Xe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on OsXe(O2F3)2 by Materials Project

XeOF4OsO3F2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one OsO3F2 cluster and two XeOF4 clusters. In the OsO3F2 cluster, Os is bonded in a 6-coordinate geometry to three O and three F atoms. All Os–O bond lengths are 1.71 Å. There are a spread of Os–F bond distances ranging from 1.96–2.16 Å. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Os atom. In the second O site, O is bonded in a single-bond geometry to one Os atom. In the third O site, O is bonded in a single-bond geometry to one Os atom. There are two inequivalent F sites. In the first F site, F is bonded in a water-like geometry to two equivalent Os atoms. In the second F site, F is bonded in a single-bond geometry to one Os atom. In each XeOF4 cluster, Xe is bonded in a square pyramidal geometry to one O and four F atoms. The Xe–O bond length is 1.83 Å. There are two shorter (2.03 Å) and two longer (2.04 Å) Xe–F bond lengths. O is bonded in a single-bond geometry to one Xe atom. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Xe atom. In the second F site, F is bonded in a single-bond geometry to one Xe atom. In the third F site, F is bonded in a single-bond geometry to one Xe atom. In the fourth F site, F is bonded in a single-bond geometry to one Xe atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(OsO3)2 by Materials Project

KOs2O6 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.99 Å) and three longer (3.35 Å) K–O bond lengths. In the second K1+ site, K1+ is bonded to six O2- atoms to form KO6 octahedra that share corners with twelve OsO6 octahedra. The corner-sharing octahedra tilt angles range from 69–70°. There are three shorter (3.14 Å) and three longer (3.17 Å) K–O bond lengths. There are two inequivalent Os+5.50+ sites. In the first Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with three equivalent KO6 octahedra and corners with six OsO6 octahedra. The corner-sharing octahedra tilt angles range from 40–70°. There are a spread of Os–O bond distances ranging from 1.92–1.94 Å. In the second Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with three equivalent KO6 octahedra and corners with six equivalent OsO6 octahedra. The corner-sharing octahedra tilt angles range from 40–69°. All Os–O bond lengths are 1.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Os+5.50+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Os+5.50+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two equivalent Os+5.50+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Os+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Logic in Memory Emulator

Logic in Memory Emulator (LiME) is a hardware/software tool specially designed for memory system evaluation and experiment. Emerging memories display a wide range of bandwidths, latencies, and capacities, making it challenging for the computer architect to navigate the design space of potential memory configurations, and for the application developer to assess performance implications of using such memories. With the LiME framework, architectural ideas can be prototyped in great detail yet with sufficient performance to support realistic evaluation on long running applications. LiME consists of two fundamental components: 1) the hardware and OS infrastructure for the emulator, and 2) a suite of benchmark applications to assist in characterizing the performance of current and future computer architectures. Some of the applications have been collected from other open source projects. Uses: Logging, replay and analysis of an application's memory behavior Evaluate impact of emerging memory technology on application performance. Emulate complex memory interactions in whole applications orders of magnitude faster than software simulation. Emulate acceleration hardware co-located with the memory subsystem. Features: Capture and log external memory accesses to a separate off-chip memory device without affecting application execution. Memory traces include the address, length, timestamp, and optionally the data for each transaction. Captured trace data can be saved to an SD card for off-line analysis. Configure a wide range of memory latencies in sub-nanosecond increments that encompass highbandwidth and storage class memories. Specify regions of interest (ROI) in applications to reduce the amount of trace data captured for analysis. Currently supports execution on Xilinx Zynq SoC which integrates an ARM processor with FPGA logic on a single device. Applications can be run under Linux or in bare metal mode on the ARM cores.

Jain, AbhishekK↗
DOE OSTI2020

Materials Data on Ca2B5Os3 by Materials Project

Ca2Os3B5 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Ca2+ is bonded in a 2-coordinate geometry to two equivalent Os+0.33- and seven B+0.60- atoms. There are one shorter (3.23 Å) and one longer (3.26 Å) Ca–Os bond lengths. There are a spread of Ca–B bond distances ranging from 2.70–3.20 Å. There are two inequivalent Os+0.33- sites. In the first Os+0.33- site, Os+0.33- is bonded in a 6-coordinate geometry to four equivalent Ca2+ and six B+0.60- atoms. There are a spread of Os–B bond distances ranging from 2.18–2.25 Å. In the second Os+0.33- site, Os+0.33- is bonded in a 5-coordinate geometry to five B+0.60- atoms. There are a spread of Os–B bond distances ranging from 1.96–2.27 Å. There are three inequivalent B+0.60- sites. In the first B+0.60- site, B+0.60- is bonded to four equivalent Ca2+ and two equivalent Os+0.33- atoms to form edge-sharing BCa4Os2 octahedra. In the second B+0.60- site, B+0.60- is bonded in a 7-coordinate geometry to two equivalent Ca2+, three Os+0.33-, and two B+0.60- atoms. There is one shorter (1.66 Å) and one longer (1.72 Å) B–B bond length. In the third B+0.60- site, B+0.60- is bonded in a 5-coordinate geometry to three equivalent Ca2+, four Os+0.33-, and one B+0.60- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sm3Os by Materials Project

Sm3Os is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 2-coordinate geometry to three equivalent Os atoms. There are a spread of Sm–Os bond distances ranging from 2.90–3.32 Å. In the second Sm site, Sm is bonded in a distorted bent 150 degrees geometry to two equivalent Os atoms. There are one shorter (2.84 Å) and one longer (2.89 Å) Sm–Os bond lengths. Os is bonded in a 6-coordinate geometry to eight Sm atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd3Os by Materials Project

Nd3Os is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Nd sites. In the first Nd site, Nd is bonded in a 2-coordinate geometry to three equivalent Os atoms. There are a spread of Nd–Os bond distances ranging from 2.91–3.39 Å. In the second Nd site, Nd is bonded in a distorted bent 150 degrees geometry to two equivalent Os atoms. There are one shorter (2.86 Å) and one longer (2.92 Å) Nd–Os bond lengths. Os is bonded in a 6-coordinate geometry to eight Nd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li5OsO6 by Materials Project

Li5OsO6 is Caswellsilverite-like structured and crystallizes in the trigonal P3_112 space group. The structure is three-dimensional. there are five inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six LiO6 octahedra, edges with three equivalent OsO6 octahedra, and edges with nine LiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–11°. All Li–O bond lengths are 2.09 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four LiO6 octahedra, edges with two equivalent OsO6 octahedra, and edges with ten LiO6 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. There are four shorter (2.07 Å) and two longer (2.25 Å) Li–O bond lengths. In the third Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four LiO6 octahedra, edges with two equivalent OsO6 octahedra, and edges with ten LiO6 octahedra. The corner-sharing octahedra tilt angles range from 1–11°. There are a spread of Li–O bond distances ranging from 2.08–2.16 Å. In the fourth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six LiO6 octahedra, edges with three equivalent OsO6 octahedra, and edges with nine LiO6 octahedra. The corner-sharing octahedra tilt angles range from 8–11°. There are four shorter (2.09 Å) and two longer (2.10 Å) Li–O bond lengths. In the fifth Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with two equivalent OsO6 octahedra, corners with four LiO6 octahedra, edges with two equivalent OsO6 octahedra, and edges with ten LiO6 octahedra. The corner-sharing octahedra tilt angles range from 2–11°. There are two shorter (2.08 Å) and four longer (2.16 Å) Li–O bond lengths. Os7+ is bonded to six O2- atoms to form OsO6 octahedra that share corners with six LiO6 octahedra and edges with twelve LiO6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are a spread of Os–O bond distances ranging from 1.90–1.93 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five Li1+ and one Os7+ atom to form a mixture of edge and corner-sharing OLi5Os octahedra. The corner-sharing octahedra tilt angles range from 0–13°. In the second O2- site, O2- is bonded to five Li1+ and one Os7+ atom to form a mixture of edge and corner-sharing OLi5Os octahedra. The corner-sharing octahedra tilt angles range from 0–7°. In the third O2- site, O2- is bonded to five Li1+ and one Os7+ atom to form a mixture of edge and corner-sharing OLi5Os octahedra. The corner-sharing octahedra tilt angles range from 0–12°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr3Os by Materials Project

Pr3Os is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Pr sites. In the first Pr site, Pr is bonded in a 2-coordinate geometry to three equivalent Os atoms. There are a spread of Pr–Os bond distances ranging from 2.93–3.46 Å. In the second Pr site, Pr is bonded in a bent 150 degrees geometry to two equivalent Os atoms. There are one shorter (2.89 Å) and one longer (2.94 Å) Pr–Os bond lengths. Os is bonded in a 6-coordinate geometry to eight Pr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Th(GeOs)2 by Materials Project

Th(OsGe)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Th is bonded in a 8-coordinate geometry to eight equivalent Os and eight equivalent Ge atoms. All Th–Os bond lengths are 3.30 Å. All Th–Ge bond lengths are 3.31 Å. Os is bonded in a 4-coordinate geometry to four equivalent Th and four equivalent Ge atoms. All Os–Ge bond lengths are 2.48 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Th, four equivalent Os, and one Ge atom. The Ge–Ge bond length is 2.58 Å.

36 MATERIALS SCIENCE↗
NASA NTRS2007

High-Precision Nd Isotopes in Picrites from Hawaii and Iceland - No Evidence for an Early-Formed Enriched Reservoir

New high-precision Nd isotope measurements have shown that the present-day Nd-142/Nd-144 for average chondrites is approximately 20 ppm lower than that for the terrestrial standard and all recent mantle-derived samples measured to date. One explanation for these differences is that an enriched missing reservoir with lower Nd-142/Nd-144 resides in the mantle to balance the bulk Earth to chondritic. Data from Archean Greenland rocks show anomalies in Nd-142/Nd-144 of up to 40 ppm higher than the proposed average for chondrites. This difference between the Archean Greenland rocks and present-day mantle-derived samples has been interpreted to result from remixing of an early-formed enriched reservoir into the convecting mantle during the Archean. If so, the implication from this is that remixing of the enriched reservoir largely shut down some time in the past such that it must at present reside in a region in the mantle that infrequently participates dynamically and leading to volcanism at the surface. Several studies have suggested that the missing reservoir may be present just above the coremantle boundary (CMB). Depending on the size of this reservoir it could potentially make up all of D or exist as distinct domains within it. If such a reservoir does exist, then mantle-derived samples from plume systems that are thought to come from the CMB may be the best opportunity to identify this component using high-precision Nd isotope measurements. To test this, picrites from Hawaii with coupled enrichments in Os-186-Os-187 that has been proposed to be a signature of core-mantle interaction were measured on the JSC Triton for high-precision Nd-142/Nd-144. For comparison, picrites from Hawaii and Iceland that do not show coupled enrichments in Os-186-Os-187 were measured. We have established an external precision for Nd-142/Nd-144 of 3.6 ppm (2 sigma) during the analytical campaign. The Iceland (n=5) and Hawaiian data (n=9) have Nd-142 ranging from -0.01 plus or minus 0.03 to +0.03 plus or minus 0.03 (2 sigma) and there is no resolvable difference between samples with Os isotope enrichments versus those without. The average epsilon Nd-142 of +0.011 plus or minus 0.034 (2 sigma ) for all of the samples (n=14) is not resolvable from the Ames and La Jolla standards with epsilon Nd-142 of +0.000 plus or minus 0.036 (n=16, 2 sigma). These data confirm recent measurements on lavas for the absence of an ancient enriched Nd-142 isotopic signature in plume systems likely derived from D and indicates that such a reservoir, if existing, must now reside in areas of the deep mantle that plumes do not sample.

Brandon, A. D.↗
DOE OSTI2020

Materials Data on Nd(Al5Os)2 by Materials Project

Nd(OsAl5)2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Nd is bonded in a 10-coordinate geometry to four equivalent Os and sixteen Al atoms. All Nd–Os bond lengths are 3.49 Å. There are a spread of Nd–Al bond distances ranging from 3.19–3.70 Å. Os is bonded in a 10-coordinate geometry to two equivalent Nd and ten Al atoms. There are a spread of Os–Al bond distances ranging from 2.58–2.77 Å. There are five inequivalent Al sites. In the first Al site, Al is bonded in a 2-coordinate geometry to one Nd and two equivalent Os atoms. In the second Al site, Al is bonded in a distorted linear geometry to two equivalent Nd and two equivalent Os atoms. In the third Al site, Al is bonded in a 2-coordinate geometry to two equivalent Nd and two equivalent Os atoms. In the fourth Al site, Al is bonded in a distorted bent 120 degrees geometry to two equivalent Nd and two equivalent Os atoms. In the fifth Al site, Al is bonded in a 2-coordinate geometry to one Nd and two equivalent Os atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K(OsO3)2 by Materials Project

KOs2O6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. K1+ is bonded in a 11-coordinate geometry to eleven O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.21 Å. There are two inequivalent Os+5.50+ sites. In the first Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing OsO6 octahedra. The corner-sharing octahedra tilt angles range from 38–45°. There are a spread of Os–O bond distances ranging from 1.93–1.99 Å. In the second Os+5.50+ site, Os+5.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing OsO6 octahedra. The corner-sharing octahedra tilt angles range from 38–45°. There are a spread of Os–O bond distances ranging from 1.89–1.96 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Os+5.50+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two Os+5.50+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+ and two Os+5.50+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Os+5.50+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two Os+5.50+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Os+5.50+ atoms.

36 MATERIALS SCIENCE↗