Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “cluster structure”

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

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

At least 955 records · Page 53
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NiF4 by Materials Project

NiF4 is alpha Po structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two NiF4 clusters. Ni4+ is bonded in a square co-planar geometry to four F1- atoms. All Ni–F bond lengths are 1.75 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Ni4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Ni4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu(ClO)2 by Materials Project

CuO2Cl2 is alpha Po structured and crystallizes in the orthorhombic Pmna space group. The structure is zero-dimensional and consists of two CuO2Cl2 clusters. Cu is bonded in a square co-planar geometry to two equivalent O and two equivalent Cl atoms. Both Cu–O bond lengths are 1.77 Å. Both Cu–Cl bond lengths are 2.19 Å. O is bonded in a single-bond geometry to one Cu atom. Cl is bonded in a single-bond geometry to one Cu atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Filaments in and between galaxy clusters at low and mid-frequency with the SKA

Context. Understanding the magnetised Universe is a major challenge in modern astrophysics, and cosmic magnetism has been acknowledged as one of the key scientific drivers of the most ambitious radio instrument ever planned, the Square Kilometre Array. Aims. With this work, we aim to investigate the potential of the Square Kilometre Array and its precursors and pathfinders in the study of magnetic fields in galaxy clusters and filaments through diffuse synchrotron radio emission. Galaxy clusters and filaments of the cosmic web are indeed unique laboratories in which to investigate turbulent fluid motions and large-scale magnetic fields in action, and much of what is known about magnetic fields in galaxy clusters comes from sensitive radio observations. Methods. Based on cosmological magneto-hydrodynamic simulations, we predict radio properties (total intensity and polarisation) of a pair of galaxy clusters connected by a cosmic-web filament. Results. We use our theoretical expectations to explore the potential of polarimetric observations to study large-scale structure magnetic fields in the frequency ranges 50–350 MHz and 950–1760 MHz. We also present predictions for galaxy cluster polarimetric observations with the Square Kilometre Array precursors and pathfinders, such as the LOw frequency ARray 2.0 and the MeerKAT+ telescope. Conclusions. Our findings point out that polarisation observations are particularly powerful for the study of large-scale magnetic fields, since they are not significantly affected by confusion noise. The unprecedented sensitivity and spatial resolution of the intermediatefrequency radio telescopes make them the favourite instruments for the study of these sources through polarimetric data, potentially allowing us to understand if the energy density of relativistic electrons is in equipartition with the magnetic field or rather coupled with the thermal gas density. Our results show that low-frequency instruments also represent a precious tool to study diffuse synchrotron emission in total intensity and polarisation.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Water Defect Stabilizes the Bi 3+ Lone-Pair Electronic State Leading to an Unusual Aqueous Hydration Structure

In this work, the aqueous hydration structure of Bi 3+ is probed using a combination of extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DFT) simulations of ion-water clusters and of condensed-phase solutions. Anomalous features in the EXAFS spectra are found to be associated with a highly asymmetric first-solvent water shell. The aqueous chemistry and structure of the Bi 3+ ion is dramatically controlled by the water stabilization of a lone-pair electronic state involving the mixed 6s and 6p orbitals. This leads to a distinct multi-modal distribution of waters in the first shell that are separated by about 0.2Å. The lone-pair structure is stabilized by a collective response of multiple waters that are localized near the lone-pair anti-bonding site. The findings indicate that the lone-pair stereochemistry of aqueous Bi 3+ plays a major role in the binding of water and ligands in aqueous solutions.

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

Materials Data on SbS2NF6 by Materials Project

NS2SbF6 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of two NS2 clusters and two SbF6 clusters. In each NS2 cluster, N5+ is bonded in a linear geometry to two equivalent S2- atoms. Both N–S bond lengths are 1.49 Å. S2- is bonded in a distorted single-bond geometry to one N5+ atom. In each SbF6 cluster, Sb5+ is bonded in an octahedral geometry to six F1- atoms. There is two shorter (1.92 Å) and four longer (1.93 Å) Sb–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Sb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AlS2NCl4 by Materials Project

AlCl4NS2 is Modderite structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four AlCl4 clusters and four NS2 clusters. In each AlCl4 cluster, Al3+ is bonded in a tetrahedral geometry to four Cl1- atoms. All Al–Cl bond lengths are 2.16 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In the second Cl1- site, Cl1- is bonded in a distorted single-bond geometry to one Al3+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one Al3+ atom. In each NS2 cluster, N5+ is bonded in a linear geometry to two S2- atoms. Both N–S bond lengths are 1.50 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a single-bond geometry to one N5+ atom. In the second S2- site, S2- is bonded in a distorted single-bond geometry to one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NiSeO10 by Materials Project

NiO6SeO4 crystallizes in the tetragonal P4_12_12 space group. The structure is zero-dimensional and consists of four NiO6 clusters and four SeO4 clusters. In each NiO6 cluster, Ni is bonded in an octahedral geometry to six O atoms. There are a spread of Ni–O bond distances ranging from 1.80–1.87 Å. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ni atom. In the second O site, O is bonded in a single-bond geometry to one Ni atom. In the third O site, O is bonded in a single-bond geometry to one Ni atom. In each SeO4 cluster, Se is bonded in a tetrahedral geometry to four O atoms. There is two shorter (1.69 Å) and two longer (1.70 Å) Se–O bond length. There are two inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Se atom. In the second O site, O is bonded in a single-bond geometry to one Se atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaS2 by Materials Project

TaS2 is Cyanogen Chloride-derived structured and crystallizes in the hexagonal P6/mmm space group. The structure is zero-dimensional and consists of two TaS2 clusters. Ta4+ is bonded in a linear geometry to two S2- atoms. There are one shorter (2.34 Å) and one longer (2.35 Å) Ta–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a single-bond geometry to one Ta4+ atom. In the second S2- site, S2- is bonded in a single-bond geometry to one Ta4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AuXeF9 by Materials Project

XeF5AuF4 crystallizes in the tetragonal I4/m space group. The structure is zero-dimensional and consists of four AuF4 clusters and four XeF5 clusters. In each AuF4 cluster, Au is bonded in a square co-planar geometry to four equivalent F atoms. All Au–F bond lengths are 1.97 Å. F is bonded in a single-bond geometry to one Au atom. In each XeF5 cluster, Xe is bonded in a distorted square pyramidal geometry to five F atoms. All Xe–F bond lengths are 1.99 Å. There are two 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.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge(SF6)2 by Materials Project

GeF6(SF3)2 crystallizes in the orthorhombic Pnnm space group. The structure is zero-dimensional and consists of two GeF6 clusters and four SF3 clusters. In each GeF6 cluster, Ge4+ is bonded in an octahedral geometry to six F1- atoms. There is two shorter (1.83 Å) and four longer (1.84 Å) Ge–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Ge4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Ge4+ atom. In each SF3 cluster, S4+ is bonded in a 3-coordinate geometry to three F1- atoms. There is one shorter (1.56 Å) and two longer (1.57 Å) S–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one S4+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one S4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SNF by Materials Project

NSF crystallizes in the tetragonal P-42_1c space group. The structure is zero-dimensional and consists of two NSF clusters. N3+ is bonded in a bent 120 degrees geometry to two equivalent S2- atoms. There is one shorter (1.55 Å) and one longer (1.67 Å) N–S bond length. S2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent N3+ and one F1- atom. The S–F bond length is 1.67 Å. F1- is bonded in a single-bond geometry to one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SNF by Materials Project

NSF crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of six NSF clusters. N3+ is bonded in a bent 120 degrees geometry to two equivalent S2- atoms. There is one shorter (1.60 Å) and one longer (1.61 Å) N–S bond length. S2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent N3+ and one F1- atom. The S–F bond length is 1.67 Å. F1- is bonded in a single-bond geometry to one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbOF by Materials Project

SbOF crystallizes in the tetragonal P-42_1c space group. The structure is zero-dimensional and consists of two SbOF clusters. Sb3+ is bonded in a distorted T-shaped geometry to two equivalent O2- and one F1- atom. There is one shorter (1.96 Å) and one longer (2.00 Å) Sb–O bond length. The Sb–F bond length is 1.97 Å. O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Sb3+ atoms. F1- is bonded in a single-bond geometry to one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PtCl2 by Materials Project

PtCl2 is Tungsten structured and crystallizes in the trigonal R-3m space group. The structure is zero-dimensional and consists of three PtCl2 clusters. Pt2+ is bonded in a rectangular see-saw-like geometry to four Cl1- atoms. All Pt–Cl bond lengths are 2.33 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in an L-shaped geometry to two equivalent Pt2+ atoms. In the second Cl1- site, Cl1- is bonded in an L-shaped geometry to two equivalent Pt2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PdCl2 by Materials Project

PdCl2 is Tungsten structured and crystallizes in the trigonal R-3 space group. The structure is zero-dimensional and consists of three PdCl2 clusters. Pd2+ is bonded in a rectangular see-saw-like geometry to four Cl1- atoms. All Pd–Cl bond lengths are 2.34 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in an L-shaped geometry to two equivalent Pd2+ atoms. In the second Cl1- site, Cl1- is bonded in an L-shaped geometry to two equivalent Pd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on IF3 by Materials Project

IF3 is High Pressure (4-7GPa) Tellurium structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four IF3 clusters. I is bonded in a T-shaped geometry to three F atoms. There is one shorter (1.91 Å) and two longer (2.02 Å) I–F bond length. There are two inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one I atom. In the second F site, F is bonded in a single-bond geometry to one I atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NClO by Materials Project

NOCl crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two NOCl clusters. N3+ is bonded in a single-bond geometry to one O2- and two equivalent Cl1- atoms. The N–O bond length is 1.14 Å. There are one shorter (2.37 Å) and one longer (2.42 Å) N–Cl bond lengths. O2- is bonded in a single-bond geometry to one N3+ atom. Cl1- is bonded in a 2-coordinate geometry to two equivalent N3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2022

A New Member of the Milky Way’s Family Tree: Characterizing the Pontus Merger of Our Galaxy

We study the Pontus structure—a recently discovered merger that brought in ~7 globular clusters in the course of the hierarchical buildup of the Milky Way’s halo. Here, we analyze the stellar population of Pontus and examine (1) its phase-space distribution using the ESA/Gaia data set, (2) its metallicity and chemical abundances (i.e., [Fe/H], [ α /Fe], [Mg/Fe], and [Al/Fe]) using the spectroscopic catalog of APOGEE DR17, and (3) the color–magnitude diagram that shows interesting features, including a possibly double horizontal branch and a small population of blue stragglers. In sum, the Pontus stars show some unique properties that suggest they likely originated from the merging of an independent satellite galaxy; however, future analysis will shed more light on the true nature of this structure. This chemodynamical analysis of Pontus stars is another step forward in our bigger quest to characterize all the merging events of our Milky Way.

79 ASTRONOMY AND ASTROPHYSICS↗