Search NASA⌕ Search

SEARCH · Search NASA

Results for “Projective geometries”

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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on BaTiO3 by Materials Project

BaTiO3 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a linear geometry to two equivalent O2- atoms. Both Ba–O bond lengths are 2.52 Å. Ti4+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Ti–O bond lengths are 2.06 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ti4+ and two equivalent O2- atoms. Both O–O bond lengths are 2.06 Å. In the second O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent O2- atoms to form distorted corner-sharing OBa2O4 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(PS3)2 by Materials Project

TiP2S6 crystallizes in the orthorhombic Fdd2 space group. The structure is three-dimensional. Ti2+ is bonded in an octahedral geometry to six S2- atoms. There are two shorter (2.43 Å) and four longer (2.46 Å) Ti–S bond lengths. P5+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of P–S bond distances ranging from 2.02–2.05 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in an L-shaped geometry to one Ti2+ and one P5+ atom. In the second S2- site, S2- is bonded in a water-like geometry to one Ti2+ and one P5+ atom. In the third S2- site, S2- is bonded in an L-shaped geometry to one Ti2+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on VAg3O4 by Materials Project

Ag3VO4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. V5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.75 Å) and two longer (1.78 Å) V–O bond length. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.18–2.60 Å. In the second Ag1+ site, Ag1+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.31 Å) and two longer (2.50 Å) Ag–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one V5+ and three Ag1+ atoms to form distorted corner-sharing OVAg3 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one V5+ and three Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on VAgHgO4 by Materials Project

VAgHgO4 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. V5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of V–O bond distances ranging from 1.71–1.85 Å. Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.33–3.04 Å. There are two inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Hg–O bond distances ranging from 2.28–2.64 Å. In the second Hg2+ site, Hg2+ is bonded in a 2-coordinate geometry to six O2- atoms. There are a spread of Hg–O bond distances ranging from 2.06–2.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one V5+, one Ag1+, and one Hg2+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one V5+, two equivalent Ag1+, and one Hg2+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one V5+, two equivalent Ag1+, and two Hg2+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one V5+, one Ag1+, and two Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PBr5 by Materials Project

PBr5 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. P5+ is bonded in a tetrahedral geometry to four Br1- atoms. There are one shorter (2.20 Å) and three longer (2.22 Å) P–Br bond lengths. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a single-bond geometry to one P5+ and one Br1- atom. The Br–Br bond length is 3.14 Å. In the second Br1- site, Br1- is bonded in a single-bond geometry to one P5+ and one Br1- atom. The Br–Br bond length is 3.05 Å. In the third Br1- site, Br1- is bonded in a see-saw-like geometry to four Br1- atoms. The Br–Br bond length is 3.26 Å. In the fourth Br1- site, Br1- is bonded in a single-bond geometry to one P5+ and one Br1- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ge(Bi3O5)4 by Materials Project

Bi12GeO20 crystallizes in the cubic I23 space group. The structure is three-dimensional. Ge4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Ge–O bond lengths are 1.80 Å. Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.11–2.66 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Bi3+ atoms. In the second O2- site, O2- is bonded to one Ge4+ and three equivalent Bi3+ atoms to form distorted corner-sharing OGeBi3 tetrahedra. In the third O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl4CrI6 by Materials Project

CrTl4I6 crystallizes in the orthorhombic Cccm space group. The structure is three-dimensional. Cr2+ is bonded in an octahedral geometry to six I1- atoms. There are a spread of Cr–I bond distances ranging from 2.75–3.34 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 6-coordinate geometry to six I1- atoms. There are a spread of Tl–I bond distances ranging from 3.41–3.74 Å. In the second Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Tl–I bond distances ranging from 3.53–3.93 Å. There are three inequivalent I1- sites. In the first I1- site, I1- is bonded in a 7-coordinate geometry to one Cr2+ and six Tl1+ atoms. In the second I1- site, I1- is bonded in a 1-coordinate geometry to one Cr2+ and four Tl1+ atoms. In the third I1- site, I1- is bonded to one Cr2+ and four Tl1+ atoms to form distorted corner-sharing ITl4Cr square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si(Bi3O5)4 by Materials Project

Bi12SiO20 crystallizes in the cubic I23 space group. The structure is three-dimensional. Si4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Si–O bond lengths are 1.67 Å. Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.11–2.68 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Si4+ and three equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti(Bi3O5)4 by Materials Project

Bi12TiO20 crystallizes in the cubic I23 space group. The structure is three-dimensional. Ti4+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Ti–O bond lengths are 1.85 Å. Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.11–2.65 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ti4+ and three equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgH12SO9 by Materials Project

MgH12SO9 crystallizes in the trigonal R3 space group. The structure is three-dimensional. Mg2+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.07 Å) and three longer (2.16 Å) Mg–O bond lengths. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.70 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.68 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (0.99 Å) and one longer (1.77 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. S4+ is bonded in a trigonal non-coplanar geometry to three equivalent O2- atoms. All S–O bond lengths are 1.56 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Mg2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two H1+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three H1+ and one S4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl4HgBr6 by Materials Project

Tl4HgBr6 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. Hg2+ is bonded in an octahedral geometry to six Br1- atoms. There are two shorter (2.60 Å) and four longer (3.12 Å) Hg–Br bond lengths. Tl1+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are a spread of Tl–Br bond distances ranging from 3.32–3.84 Å. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 7-coordinate geometry to one Hg2+ and six equivalent Tl1+ atoms. In the second Br1- site, Br1- is bonded to one Hg2+ and four equivalent Tl1+ atoms to form distorted corner-sharing BrTl4Hg square pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl3CoCl5 by Materials Project

CoTl3Cl5 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Co2+ is bonded in a tetrahedral geometry to four equivalent Cl1- atoms. All Co–Cl bond lengths are 2.25 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a distorted q6 geometry to ten Cl1- atoms. There are eight shorter (3.56 Å) and two longer (3.64 Å) Tl–Cl bond lengths. In the second Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of Tl–Cl bond distances ranging from 3.21–3.51 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to six Tl1+ atoms to form corner-sharing ClTl6 octahedra. The corner-sharing octahedra tilt angles range from 0–38°. In the second Cl1- site, Cl1- is bonded in a 1-coordinate geometry to one Co2+ and five Tl1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl3FeCl5 by Materials Project

FeTl3Cl5 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Fe2+ is bonded in a tetrahedral geometry to four equivalent Cl1- atoms. All Fe–Cl bond lengths are 2.29 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 10-coordinate geometry to ten Cl1- atoms. There are eight shorter (3.55 Å) and two longer (3.73 Å) Tl–Cl bond lengths. In the second Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of Tl–Cl bond distances ranging from 3.19–3.54 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to six Tl1+ atoms to form corner-sharing ClTl6 octahedra. The corner-sharing octahedra tilt angles range from 0–38°. In the second Cl1- site, Cl1- is bonded in a 1-coordinate geometry to one Fe2+ and five Tl1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl4HgI6 by Materials Project

Tl4HgI6 crystallizes in the tetragonal P4/mnc space group. The structure is three-dimensional. Hg2+ is bonded in an octahedral geometry to six I1- atoms. There are two shorter (2.75 Å) and four longer (3.40 Å) Hg–I bond lengths. Tl1+ is bonded in a 8-coordinate geometry to eight I1- atoms. There are a spread of Tl–I bond distances ranging from 3.54–3.94 Å. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a 7-coordinate geometry to one Hg2+ and six equivalent Tl1+ atoms. In the second I1- site, I1- is bonded in a 5-coordinate geometry to one Hg2+ and four equivalent Tl1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TlFeBr4 by Materials Project

FeTlBr4 crystallizes in the orthorhombic Pnna space group. The structure is three-dimensional. Fe3+ is bonded in a tetrahedral geometry to four Br1- atoms. There are two shorter (2.36 Å) and two longer (2.37 Å) Fe–Br bond lengths. Tl1+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are a spread of Tl–Br bond distances ranging from 3.44–3.62 Å. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted single-bond geometry to one Fe3+ and two equivalent Tl1+ atoms. In the second Br1- site, Br1- is bonded in a distorted single-bond geometry to one Fe3+ and two equivalent Tl1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BeTl2F4 by Materials Project

BeTl2F4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Be2+ is bonded in a tetrahedral geometry to four F1- atoms. There are a spread of Be–F bond distances ranging from 1.56–1.59 Å. There are two inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Tl–F bond distances ranging from 2.76–3.20 Å. In the second Tl1+ site, Tl1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Tl–F bond distances ranging from 2.82–3.39 Å. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to one Be2+ and four Tl1+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one Be2+ and five Tl1+ atoms. In the third F1- site, F1- is bonded in a single-bond geometry to one Be2+ and five Tl1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgAuS2 by Materials Project

AuAgS2 crystallizes in the orthorhombic Pccm space group. The structure is three-dimensional. Au3+ is bonded in a linear geometry to two equivalent S2- atoms. Both Au–S bond lengths are 2.31 Å. Ag1+ is bonded in a 4-coordinate geometry to four equivalent S2- atoms. All Ag–S bond lengths are 2.62 Å. S2- is bonded to one Au3+, two equivalent Ag1+, and one S2- atom to form a mixture of edge and corner-sharing SAg2AuS tetrahedra. The S–S bond length is 2.13 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgH12SeO9 by Materials Project

MgH12SeO9 crystallizes in the trigonal R3 space group. The structure is three-dimensional. Mg2+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.08 Å) and three longer (2.15 Å) Mg–O bond lengths. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.71 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.70 Å) H–O bond length. Se4+ is bonded in a trigonal non-coplanar geometry to three equivalent O2- atoms. All Se–O bond lengths are 1.74 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to three H1+ and one Se4+ atom to form distorted corner-sharing OH3Se tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Mg2+ and two H1+ atoms.

36 MATERIALS SCIENCE↗