Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Pr2MgSe4”

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.

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Pr2MgSe4 by Materials Project

MgPr2Se4 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one MgPr2Se4 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four Se2- atoms to form MgSe4 tetrahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent PrSe6 octahedra, and corners with six PrSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–64°. There are a spread of Mg–Se bond distances ranging from 2.55–2.62 Å. In the second Mg2+ site, Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share a cornercorner with one MgSe4 tetrahedra, corners with five PrSe4 tetrahedra, edges with two equivalent MgSe6 octahedra, and edges with four equivalent PrSe6 octahedra. There are a spread of Mg–Se bond distances ranging from 2.82–2.91 Å. There are four inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded to four Se2- atoms to form PrSe4 tetrahedra that share a cornercorner with one PrSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four PrSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–65°. There are a spread of Pr–Se bond distances ranging from 2.81–2.85 Å. In the second Pr3+ site, Pr3+ is bonded to six Se2- atoms to form PrSe6 octahedra that share corners with two equivalent MgSe4 tetrahedra, corners with four PrSe4 tetrahedra, edges with two equivalent PrSe6 octahedra, and edges with four equivalent MgSe6 octahedra. There are a spread of Pr–Se bond distances ranging from 3.01–3.07 Å. In the third Pr3+ site, Pr3+ is bonded to four Se2- atoms to form PrSe4 tetrahedra that share a cornercorner with one PrSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four PrSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 58–68°. There are a spread of Pr–Se bond distances ranging from 2.81–2.84 Å. In the fourth Pr3+ site, Pr3+ is bonded to four Se2- atoms to form PrSe4 tetrahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent PrSe6 octahedra, corners with two equivalent MgSe4 tetrahedra, and corners with four PrSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–66°. There are a spread of Pr–Se bond distances ranging from 2.81–2.84 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Mg2+ and two Pr3+ atoms to form a mixture of distorted corner and edge-sharing SePr2Mg2 tetrahedra. In the second Se2- site, Se2- is bonded to two Mg2+ and two equivalent Pr3+ atoms to form distorted SePr2Mg2 tetrahedra that share corners with nine SePr2Mg2 tetrahedra and edges with three SePr3Mg tetrahedra. In the third Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Pr3+ atoms. In the fourth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to three Pr3+ atoms. In the fifth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Pr3+ atoms. In the sixth Se2- site, Se2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Pr3+ atoms. In the seventh Se2- site, Se2- is bonded to one Mg2+ and three Pr3+ atoms to form distorted SePr3Mg tetrahedra that share corners with nine SePr2Mg2 tetrahedra and edges with three SePr3Mg tetrahedra. In the eighth Se2- site, Se2- is bonded to two equivalent Mg2+ and two Pr3+ atoms to form distorted SePr2Mg2 tetrahedra that share corners with nine SePr2Mg2 tetrahedra and edges with three SePr3Mg tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr2MgSe4 by Materials Project

MgPr2Se4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded in a trigonal pyramidal geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.46–2.60 Å. There are two inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Pr–Se bond distances ranging from 2.92–3.28 Å. In the second Pr3+ site, Pr3+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Pr–Se bond distances ranging from 2.82–3.11 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to one Mg2+ and four Pr3+ atoms. In the second Se2- site, Se2- is bonded in a T-shaped geometry to one Mg2+ and two Pr3+ atoms. In the third Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Pr3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr2MgSe4 by Materials Project

MgPr2Se4 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share a cornercorner with one PrSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with four PrSe7 pentagonal bipyramids, an edgeedge with one MgSe6 octahedra, edges with four PrSe6 octahedra, and edges with three PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–53°. There are a spread of Mg–Se bond distances ranging from 2.65–3.14 Å. In the second Mg2+ site, Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share a cornercorner with one PrSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with four PrSe7 pentagonal bipyramids, an edgeedge with one MgSe6 octahedra, edges with four PrSe6 octahedra, and edges with three PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–53°. There are a spread of Mg–Se bond distances ranging from 2.66–3.01 Å. There are four inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded to six Se2- atoms to form PrSe6 octahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent PrSe6 octahedra, corners with four PrSe7 pentagonal bipyramids, an edgeedge with one PrSe6 octahedra, edges with four MgSe6 octahedra, and edges with three PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–53°. There are a spread of Pr–Se bond distances ranging from 2.91–3.00 Å. In the second Pr3+ site, Pr3+ is bonded to six Se2- atoms to form PrSe6 octahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent PrSe6 octahedra, corners with four PrSe7 pentagonal bipyramids, an edgeedge with one PrSe6 octahedra, edges with four MgSe6 octahedra, and edges with three PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 11–53°. There are a spread of Pr–Se bond distances ranging from 2.91–3.03 Å. In the third Pr3+ site, Pr3+ is bonded to seven Se2- atoms to form distorted PrSe7 pentagonal bipyramids that share corners with four MgSe6 octahedra, corners with four PrSe6 octahedra, edges with three MgSe6 octahedra, edges with three PrSe6 octahedra, and faces with two equivalent PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–71°. There are a spread of Pr–Se bond distances ranging from 2.97–3.25 Å. In the fourth Pr3+ site, Pr3+ is bonded to seven Se2- atoms to form distorted PrSe7 pentagonal bipyramids that share corners with four MgSe6 octahedra, corners with four PrSe6 octahedra, edges with three MgSe6 octahedra, edges with three PrSe6 octahedra, and faces with two equivalent PrSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 16–72°. There are a spread of Pr–Se bond distances ranging from 2.96–3.29 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two Mg2+ and three Pr3+ atoms to form distorted SePr3Mg2 trigonal bipyramids that share corners with two equivalent SePr3Mg2 square pyramids, corners with three equivalent SePr3Mg tetrahedra, corners with two equivalent SePr3Mg2 trigonal bipyramids, edges with five SePr3Mg2 square pyramids, and edges with three SePr3Mg2 trigonal bipyramids. In the second Se2- site, Se2- is bonded to two Mg2+ and three Pr3+ atoms to form distorted SePr3Mg2 trigonal bipyramids that share corners with six SePr3Mg2 square pyramids, corners with two equivalent SePr3Mg tetrahedra, corners with two equivalent SePr3Mg2 trigonal bipyramids, edges with three SePr3Mg2 square pyramids, an edgeedge with one SePr3Mg tetrahedra, and edges with three SePr3Mg2 trigonal bipyramids. In the third Se2- site, Se2- is bonded to one Mg2+ and three Pr3+ atoms to form a mixture of distorted corner and edge-sharing SePr3Mg tetrahedra. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Pr3+ atoms. In the fifth Se2- site, Se2- is bonded to two Mg2+ and three Pr3+ atoms to form distorted SePr3Mg2 square pyramids that share a cornercorner with one SePr3Mg tetrahedra, corners with eight SePr3Mg2 trigonal bipyramids, edges with four SePr3Mg2 square pyramids, an edgeedge with one SePr3Mg tetrahedra, and edges with two SePr3Mg2 trigonal bipyramids. In the sixth Se2- site, Se2- is bonded to two Mg2+ and three Pr3+ atoms to form SePr3Mg2 square pyramids that share corners with two equivalent SePr4Mg square pyramids, a cornercorner with one SePr3Mg tetrahedra, corners with six SePr3Mg2 trigonal bipyramids, edges with three SePr3Mg2 square pyramids, an edgeedge with one SePr3Mg tetrahedra, and edges with three SePr3Mg2 trigonal bipyramids. In the seventh Se2- site, Se2- is bonded to one Mg2+ and four Pr3+ atoms to form distorted SePr4Mg square pyramids that share corners with two equivalent SePr3Mg2 square pyramids, corners with two equivalent SePr3Mg tetrahedra, corners with two equivalent SePr4Mg trigonal bipyramids, edges with three SePr3Mg2 square pyramids, an edgeedge with one SePr3Mg tetrahedra, and edges with five SePr3Mg2 trigonal bipyramids. In the eighth Se2- site, Se2- is bonded to one Mg2+ and four Pr3+ atoms to form distorted SePr4Mg trigonal bipyramids that share corners with eight SePr3Mg2 square pyramids, corners with three equivalent SePr3Mg tetrahedra, edges with two SePr3Mg2 square pyramids, and edges with four SePr3Mg2 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr2MgSe4 by Materials Project

MgPr2Se4 crystallizes in the tetragonal I-42d space group. The structure is three-dimensional. Mg2+ is bonded in a distorted square co-planar geometry to four equivalent Se2- atoms. All Mg–Se bond lengths are 2.76 Å. Pr3+ is bonded in a 8-coordinate geometry to eight equivalent Se2- atoms. There are a spread of Pr–Se bond distances ranging from 2.92–3.35 Å. Se2- is bonded in a 5-coordinate geometry to one Mg2+ and four equivalent Pr3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr2MgSe4 by Materials Project

MgPr2Se4 is Spinel structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Mg2+ is bonded to four equivalent Se2- atoms to form MgSe4 tetrahedra that share corners with twelve equivalent PrSe6 octahedra. The corner-sharing octahedral tilt angles are 55°. All Mg–Se bond lengths are 2.66 Å. Pr3+ is bonded to six equivalent Se2- atoms to form PrSe6 octahedra that share corners with six equivalent MgSe4 tetrahedra and edges with six equivalent PrSe6 octahedra. All Pr–Se bond lengths are 2.99 Å. Se2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three equivalent Pr3+ atoms.

36 MATERIALS SCIENCE↗