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At least 469 records · Page 26
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DOE OSTI2020

Materials Data on Cs2La10Os2I17 by Materials Project

Cs2La10Os2I17 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Cs is bonded in a 12-coordinate geometry to twelve I atoms. There are a spread of Cs–I bond distances ranging from 4.25–4.61 Å. There are four inequivalent La sites. In the first La site, La is bonded to one Os and five I atoms to form a mixture of corner and edge-sharing LaOsI5 octahedra. The corner-sharing octahedra tilt angles range from 1–9°. The La–Os bond length is 2.89 Å. There are a spread of La–I bond distances ranging from 3.22–3.50 Å. In the second La site, La is bonded to one Os and five I atoms to form distorted LaOsI5 octahedra that share corners with five LaOs2I4 octahedra and edges with five LaOsI5 octahedra. The corner-sharing octahedra tilt angles range from 6–9°. The La–Os bond length is 2.84 Å. There are a spread of La–I bond distances ranging from 3.28–3.52 Å. In the third La site, La is bonded to two equivalent Os and four I atoms to form a mixture of distorted corner and edge-sharing LaOs2I4 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are one shorter (2.86 Å) and one longer (3.02 Å) La–Os bond lengths. There are a spread of La–I bond distances ranging from 3.38–3.55 Å. In the fourth La site, La is bonded to one Os and five I atoms to form a mixture of distorted corner and edge-sharing LaOsI5 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. The La–Os bond length is 2.74 Å. There are a spread of La–I bond distances ranging from 3.26–3.52 Å. Os is bonded to six La atoms to form edge-sharing OsLa6 octahedra. There are six inequivalent I sites. In the first I site, I is bonded in a distorted T-shaped geometry to one Cs and three La atoms. In the second I site, I is bonded in a distorted T-shaped geometry to two equivalent Cs and three La atoms. In the third I site, I is bonded in a 4-coordinate geometry to one Cs and three La atoms. In the fourth I site, I is bonded in a 3-coordinate geometry to two equivalent Cs and three La atoms. In the fifth I site, I is bonded in a distorted square co-planar geometry to four La atoms. In the sixth I site, I is bonded in a 2-coordinate geometry to two equivalent Cs and two La atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsPSe6 by Materials Project

CsPSe6 crystallizes in the tetragonal P-42_1c space group. The structure is three-dimensional. there are five inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve Se1- atoms to form CsSe12 cuboctahedra that share edges with four equivalent PSe4 tetrahedra. There are a spread of Cs–Se bond distances ranging from 3.79–4.04 Å. In the second Cs1+ site, Cs1+ is bonded in a body-centered cubic geometry to eight Se1- atoms. There are four shorter (3.82 Å) and four longer (3.91 Å) Cs–Se bond lengths. In the third Cs1+ site, Cs1+ is bonded in a body-centered cubic geometry to eight Se1- atoms. There are four shorter (3.82 Å) and four longer (3.91 Å) Cs–Se bond lengths. In the fourth Cs1+ site, Cs1+ is bonded in a 12-coordinate geometry to fourteen Se1- atoms. There are a spread of Cs–Se bond distances ranging from 3.96–4.28 Å. In the fifth Cs1+ site, Cs1+ is bonded in a 12-coordinate geometry to fourteen Se1- atoms. There are a spread of Cs–Se bond distances ranging from 3.96–4.28 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four Se1- atoms to form PSe4 tetrahedra that share an edgeedge with one CsSe12 cuboctahedra. There are two shorter (2.16 Å) and two longer (2.31 Å) P–Se bond lengths. In the second P5+ site, P5+ is bonded to four Se1- atoms to form PSe4 tetrahedra that share an edgeedge with one CsSe12 cuboctahedra. There are two shorter (2.16 Å) and two longer (2.31 Å) P–Se bond lengths. There are eight inequivalent Se1- sites. In the first Se1- site, Se1- is bonded in a 4-coordinate geometry to two Cs1+ and two Se1- atoms. There are one shorter (2.39 Å) and one longer (2.42 Å) Se–Se bond lengths. In the second Se1- site, Se1- is bonded in a distorted single-bond geometry to two Cs1+, one P5+, and one Se1- atom. The Se–Cs bond length is 4.03 Å. In the third Se1- site, Se1- is bonded in a distorted single-bond geometry to two Cs1+, one P5+, and one Se1- atom. The Se–Se bond length is 2.39 Å. In the fourth Se1- site, Se1- is bonded in a 1-coordinate geometry to two Cs1+, one P5+, and one Se1- atom. The Se–Se bond length is 2.37 Å. In the fifth Se1- site, Se1- is bonded in a single-bond geometry to two Cs1+ and one P5+ atom. In the sixth Se1- site, Se1- is bonded in a 4-coordinate geometry to two Cs1+ and two Se1- atoms. The Se–Se bond length is 2.42 Å. In the seventh Se1- site, Se1- is bonded in a 4-coordinate geometry to two Cs1+ and two Se1- atoms. The Se–Cs bond length is 3.79 Å. The Se–Se bond length is 2.37 Å. In the eighth Se1- site, Se1- is bonded in a distorted single-bond geometry to two Cs1+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cs12Sn2As6O by Materials Project

Cs12Sn2As6O crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a distorted single-bond geometry to two equivalent Cs1+, four equivalent As3-, and one O2- atom. Both Cs–Cs bond lengths are 4.11 Å. There are a spread of Cs–As bond distances ranging from 3.68–4.13 Å. The Cs–O bond length is 2.98 Å. In the second Cs1+ site, Cs1+ is bonded in a 10-coordinate geometry to four Cs1+ and six equivalent As3- atoms. There are one shorter (3.74 Å) and one longer (3.76 Å) Cs–Cs bond lengths. There are two shorter (4.08 Å) and four longer (4.09 Å) Cs–As bond lengths. Sn4+ is bonded in a trigonal planar geometry to three equivalent As3- atoms. All Sn–As bond lengths are 2.59 Å. As3- is bonded in a 1-coordinate geometry to ten Cs1+ and one Sn4+ atom. O2- is bonded in an octahedral geometry to six equivalent Cs1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsTl(SO5)2 by Materials Project

CsTl(SO5)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cs is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of Cs–O bond distances ranging from 3.24–3.73 Å. Tl is bonded to six O atoms to form TlO6 octahedra that share corners with four equivalent SO4 tetrahedra. There are a spread of Tl–O bond distances ranging from 2.23–2.33 Å. S is bonded to four O atoms to form SO4 tetrahedra that share corners with two equivalent TlO6 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of S–O bond distances ranging from 1.47–1.53 Å. There are five inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cs and one Tl atom. In the second O site, O is bonded in a single-bond geometry to two equivalent Cs and one S atom. In the third O site, O is bonded in a 2-coordinate geometry to one Cs, one Tl, and one S atom. In the fourth O site, O is bonded in a single-bond geometry to one Cs and one S atom. In the fifth O site, O is bonded in a 2-coordinate geometry to one Cs, one Tl, and one S atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg6Ti by Materials Project

CsMg6Ti crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded to ten Mg and two equivalent Ti atoms to form CsMg10Ti2 cuboctahedra that share corners with four equivalent MgCs2Mg10 cuboctahedra, corners with six equivalent CsMg10Ti2 cuboctahedra, edges with two equivalent MgCs2Mg10 cuboctahedra, faces with two equivalent CsMg10Ti2 cuboctahedra, and faces with eight MgMg10Ti2 cuboctahedra. There are a spread of Cs–Mg bond distances ranging from 3.35–3.43 Å. Both Cs–Ti bond lengths are 3.56 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Cs, six Mg, and one Ti atom. There are a spread of Mg–Mg bond distances ranging from 3.31–3.42 Å. The Mg–Ti bond length is 3.03 Å. In the second Mg site, Mg is bonded to ten Mg and two equivalent Ti atoms to form distorted MgMg10Ti2 cuboctahedra that share corners with six equivalent MgMg10Ti2 cuboctahedra, edges with four equivalent MgCs2Mg10 cuboctahedra, faces with four MgMg10Ti2 cuboctahedra, and faces with six equivalent CsMg10Ti2 cuboctahedra. There are two shorter (3.33 Å) and four longer (3.40 Å) Mg–Mg bond lengths. Both Mg–Ti bond lengths are 3.39 Å. In the third Mg site, Mg is bonded in a 11-coordinate geometry to two equivalent Cs, seven Mg, and two equivalent Ti atoms. There are a spread of Mg–Mg bond distances ranging from 3.13–3.40 Å. Both Mg–Ti bond lengths are 3.21 Å. In the fourth Mg site, Mg is bonded to two equivalent Cs and ten Mg atoms to form distorted MgCs2Mg10 cuboctahedra that share corners with four equivalent CsMg10Ti2 cuboctahedra, corners with six equivalent MgCs2Mg10 cuboctahedra, edges with two equivalent CsMg10Ti2 cuboctahedra, edges with four equivalent MgMg10Ti2 cuboctahedra, faces with two equivalent CsMg10Ti2 cuboctahedra, and faces with four MgMg10Ti2 cuboctahedra. Ti is bonded in a 12-coordinate geometry to two equivalent Cs and eight Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg6Bi by Materials Project

CsMg6Bi crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded to ten Mg and two equivalent Bi atoms to form a mixture of face and corner-sharing CsMg10Bi2 cuboctahedra. There are a spread of Cs–Mg bond distances ranging from 3.50–3.62 Å. Both Cs–Bi bond lengths are 3.57 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Cs, seven Mg, and two equivalent Bi atoms. There are a spread of Mg–Mg bond distances ranging from 3.29–3.51 Å. There are one shorter (3.54 Å) and one longer (3.66 Å) Mg–Bi bond lengths. In the second Mg site, Mg is bonded in a 9-coordinate geometry to two equivalent Cs, three Mg, and two equivalent Bi atoms. The Mg–Mg bond length is 3.19 Å. Both Mg–Bi bond lengths are 3.32 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Cs and six Mg atoms. In the fourth Mg site, Mg is bonded in a distorted water-like geometry to four equivalent Mg and two equivalent Bi atoms. Both Mg–Bi bond lengths are 3.46 Å. Bi is bonded in a 12-coordinate geometry to two equivalent Cs and ten Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg6Fe by Materials Project

CsMg6Fe crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded in a 12-coordinate geometry to eight Mg and two equivalent Fe atoms. There are a spread of Cs–Mg bond distances ranging from 4.18–4.28 Å. Both Cs–Fe bond lengths are 4.25 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted single-bond geometry to one Cs, four Mg, and one Fe atom. There are two shorter (2.99 Å) and two longer (3.09 Å) Mg–Mg bond lengths. The Mg–Fe bond length is 2.63 Å. In the second Mg site, Mg is bonded in a distorted bent 120 degrees geometry to two equivalent Cs, one Mg, and two equivalent Fe atoms. The Mg–Mg bond length is 3.03 Å. Both Mg–Fe bond lengths are 2.87 Å. In the third Mg site, Mg is bonded in a distorted hexagonal planar geometry to six Mg atoms. Both Mg–Mg bond lengths are 3.09 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs and eight Mg atoms. Fe is bonded in a 6-coordinate geometry to two equivalent Cs and six Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg30SiO32 by Materials Project

CsMg30SiO32 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Cs is bonded to six O atoms to form CsO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.48 Å) and four longer (2.49 Å) Cs–O bond lengths. There are eight inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with two equivalent CsO6 octahedra, corners with two equivalent MgO6 octahedra, corners with two equivalent SiO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.85–2.48 Å. In the second Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent SiO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.37 Å) Mg–O bond lengths. In the third Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.10–2.22 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent CsO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (1.87 Å) and four longer (2.24 Å) Mg–O bond lengths. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CsO6 octahedra, an edgeedge with one SiO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are four shorter (2.17 Å) and two longer (2.21 Å) Mg–O bond lengths. In the sixth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Mg–O bond distances ranging from 2.16–2.18 Å. In the seventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one SiO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 1–16°. There are a spread of Mg–O bond distances ranging from 2.15–2.23 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CsO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. There are a spread of Mg–O bond distances ranging from 2.12–2.25 Å. Si is bonded to six O atoms to form SiO6 octahedra that share corners with six MgO6 octahedra and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.86 Å) and two longer (1.98 Å) Si–O bond length. There are twelve inequivalent O sites. In the first O site, O is bonded to five Mg and one Si atom to form a mixture of edge and corner-sharing OMg5Si octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the second O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg5Si octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the third O site, O is bonded to one Cs and five Mg atoms to form a mixture of distorted edge and corner-sharing OCsMg5 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the fourth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg5Si octahedra. The corner-sharing octahedra tilt angles range from 1–4°. In the fifth O site, O is bonded to five Mg and one Si atom to form a mixture of distorted edge and corner-sharing OMg5Si octahedra. The corner-sharing octahedra tilt angles range from 0–15°. In the sixth O site, O is bonded to one Cs and five Mg atoms to form distorted OCsMg5 octahedra that share corners with six OMg5Si octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. The O–Mg bond length is 1.85 Å. In the seventh O site, O is bonded to one Cs and five Mg atoms to form distorted OCsMg5 octahedra that share corners with six OMg5Si octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. There are a spread of O–Mg bond distances ranging from 1.85–2.25 Å. In the eighth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the ninth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are two shorter (2.15 Å) and two longer (2.17 Å) O–Mg bond lengths. In the tenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OCsMg5 octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. In the eleventh O site, O is bonded to one Cs and five Mg atoms to form distorted OCsMg5 octahedra that share corners with six OMg5Si octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. Both O–Mg bond lengths are 2.25 Å. In the twelfth O site, O is bonded to one Cs and five Mg atoms to form distorted OCsMg5 octahedra that share corners with six OMg5Si octahedra and edges with twelve OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–15°. There are two shorter (2.21 Å) and two longer (2.25 Å) O–Mg bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg6Ga by Materials Project

CsMg6Ga crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded in a 12-coordinate geometry to eight Mg and two equivalent Ga atoms. There are a spread of Cs–Mg bond distances ranging from 4.06–4.30 Å. Both Cs–Ga bond lengths are 4.07 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted single-bond geometry to one Cs, four Mg, and one Ga atom. There are two shorter (3.05 Å) and two longer (3.06 Å) Mg–Mg bond lengths. The Mg–Ga bond length is 2.80 Å. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Cs, two Mg, and two equivalent Ga atoms. There are one shorter (3.17 Å) and one longer (3.35 Å) Mg–Mg bond lengths. Both Mg–Ga bond lengths are 2.94 Å. In the third Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Cs and eight Mg atoms. Both Mg–Mg bond lengths are 3.15 Å. In the fourth Mg site, Mg is bonded in a 8-coordinate geometry to eight Mg atoms. Ga is bonded in a 8-coordinate geometry to two equivalent Cs and six Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsNaMg6 by Materials Project

CsNaMg6 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded to two equivalent Na and ten Mg atoms to form CsNa2Mg10 cuboctahedra that share corners with four equivalent NaCs2Mg10 cuboctahedra, corners with six equivalent CsNa2Mg10 cuboctahedra, edges with two equivalent NaCs2Mg10 cuboctahedra, faces with two equivalent CsNa2Mg10 cuboctahedra, and faces with two equivalent NaCs2Mg10 cuboctahedra. Both Cs–Na bond lengths are 3.40 Å. There are a spread of Cs–Mg bond distances ranging from 3.49–3.60 Å. Na is bonded to two equivalent Cs and ten Mg atoms to form NaCs2Mg10 cuboctahedra that share corners with four equivalent CsNa2Mg10 cuboctahedra, corners with six equivalent NaCs2Mg10 cuboctahedra, edges with two equivalent CsNa2Mg10 cuboctahedra, faces with two equivalent CsNa2Mg10 cuboctahedra, and faces with two equivalent NaCs2Mg10 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 3.47–3.55 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Cs, two equivalent Na, and eight Mg atoms. There are a spread of Mg–Mg bond distances ranging from 3.36–3.52 Å. In the second Mg site, Mg is bonded in a 11-coordinate geometry to two equivalent Cs, two equivalent Na, and three Mg atoms. The Mg–Mg bond length is 3.29 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Na and six Mg atoms. Both Mg–Mg bond lengths are 3.40 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Cs and eight Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsMg6Si by Materials Project

CsMg6Si crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded in a 12-coordinate geometry to eight Mg and two equivalent Si atoms. There are a spread of Cs–Mg bond distances ranging from 3.66–3.84 Å. Both Cs–Si bond lengths are 3.72 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted single-bond geometry to two equivalent Cs, five Mg, and one Si atom. There are a spread of Mg–Mg bond distances ranging from 2.94–3.23 Å. The Mg–Si bond length is 2.78 Å. In the second Mg site, Mg is bonded to six Mg atoms to form distorted face-sharing MgMg6 pentagonal pyramids. There are four shorter (3.17 Å) and two longer (3.35 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded in a distorted water-like geometry to one Cs, four Mg, and two equivalent Si atoms. Both Mg–Si bond lengths are 2.70 Å. In the fourth Mg site, Mg is bonded to two equivalent Cs and six Mg atoms to form a mixture of distorted corner and face-sharing MgCs2Mg6 hexagonal bipyramids. Si is bonded in a 8-coordinate geometry to two equivalent Cs and six Mg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsCeMg14 by Materials Project

CsMg14Ce crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Cs is bonded to ten Mg and two equivalent Ce atoms to form CsCe2Mg10 cuboctahedra that share corners with six equivalent CsCe2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent CeCs2Mg10 cuboctahedra, faces with two equivalent MgMg12 cuboctahedra, and faces with two equivalent CeCs2Mg10 cuboctahedra. There are a spread of Cs–Mg bond distances ranging from 3.36–3.53 Å. Both Cs–Ce bond lengths are 3.15 Å. There are seven inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form distorted MgMg12 cuboctahedra that share corners with four equivalent CsCe2Mg10 cuboctahedra, corners with six equivalent MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent CeCs2Mg10 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.15–3.47 Å. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with four equivalent CeCs2Mg10 cuboctahedra, corners with six equivalent MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, faces with two equivalent CsCe2Mg10 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.42 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Cs, eight Mg, and two equivalent Ce atoms. There are a spread of Mg–Mg bond distances ranging from 3.14–3.52 Å. There are one shorter (3.37 Å) and one longer (3.44 Å) Mg–Ce bond lengths. In the fourth Mg site, Mg is bonded to twelve Mg atoms to form distorted MgMg12 cuboctahedra that share corners with four equivalent CsCe2Mg10 cuboctahedra, corners with four equivalent CeCs2Mg10 cuboctahedra, corners with six equivalent MgMg12 cuboctahedra, edges with six MgMg12 cuboctahedra, and faces with six MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.12–3.31 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to one Cs, ten Mg, and one Ce atom. There are a spread of Mg–Mg bond distances ranging from 3.08–3.56 Å. The Mg–Ce bond length is 3.47 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to eleven Mg and one Ce atom. Both Mg–Mg bond lengths are 3.16 Å. The Mg–Ce bond length is 3.37 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to one Cs and eleven Mg atoms. Ce is bonded to two equivalent Cs and ten Mg atoms to form CeCs2Mg10 cuboctahedra that share corners with six equivalent CeCs2Mg10 cuboctahedra, corners with twelve MgMg12 cuboctahedra, edges with two equivalent CsCe2Mg10 cuboctahedra, faces with two equivalent CsCe2Mg10 cuboctahedra, and faces with two equivalent MgMg12 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Establishing a silica gel zone in well annulus and evaluating its performance in blocking vertical water flow

Wells are often constructed for monitoring purposes with relatively long screen lengths (e.g., >10 m). Vertical water flows can occur within the artificial or natural filterpack annulus that surrounds the screened interval, bypassing packer assemblies installed inside the wellbore. Attempts to isolate discrete vertical zones during groundwater sampling are unsuccessful when annular flow occurs and lead to remedy decisions based on biased or incorrect interpretations. Blocking vertical annular water flow and contaminant transport will help obtain more accurate concentrations of contaminants from sampling in targeted depth intervals. The application of silica gels formed from the injected colloidal silica CS suspensions is a novel approach to minimize or prevent movement of vertical movement of groundwater in the surrounding filterpack annulus. In this work, we tested the feasibility of injecting CS suspensions to target locations and developed a modified CS formulation that is injectable and prevents gravity sinking. We studied the distribution and penetration of silica gel at laboratory scale in mock well annulus with surrounding formations. We evaluated the performance of the silica gel in blocking vertical water flow in the annulus and in minimizing chemical transport through the gel zone. CS suspension formulations have been defined that are ready for injection, stay in target locations, and form gel within desired time frames. Injection of CS suspensions achieved uniform distribution in a well annulus filter pack, fully occupied the annulus pore space, and penetrated the formation surrounding the filter packer with a sufficient distance to create a hydraulic annular seal when the injection was applied at a sufficient rate. The depth of penetration into the formation was dependent on the permeability contrast between the filter pack and the surrounding formation. Silica gel that formed in the annulus blocked vertical water flow and stopped the chemical transport through the gel zone. In conclusion, this research reveals that using CS suspension injection and sequential gelation (CS-GEL) is a promising technology for blocking vertical water flow and chemical transport through the filter pack in targeted zones within the annulus of long-screened well systems.

Colloidal silica suspension↗
DOE OSTI2025

Mechanical properties and strengthening mechanisms of cold sprayed Al-Mg alloys

This paper investigates the mechanical properties and strengthening mechanisms of cold sprayed Al-Mg alloys as a function of Mg content. Cold spray (CS) is a solid-state deposition process that can be used as a repair technique for structural components. However, the limited ductility of cold sprayed materials is an unsettled issue in CS community. Herein, reproducible, and significantly increased elongation to failure (∼15%) in as-deposited conditions is reported in CS Al-Mg binary alloys with low Mg content (≤ 2.5 wt%). Furthermore, reducing Mg content down to 2.5 wt% in CS Al-Mg binary alloys demonstrated comparable mechanical strength to its wrought counterparts. Strengthening mechanisms were analyzed in wrought and CS Al-Mg alloys based upon microstructural characteristics, such as grain size, Mg solute concentration, and dislocation density. A quantitative evaluation of yield strength revealed that grain boundary strengthening is predominant in CS Al-Mg alloys as compared with their wrought counterparts. When comparing among CS Al-Mg binary alloys of different compositions, Mg solute concentration, and dislocation density governed mechanical strength. In conclusion, the underlying mechanism for the variation of mechanical properties and strengthening mechanisms is discussed in terms of these microstructural characteristics.

Additive manufacturing↗
DOE OSTI2021

Reducing Surface Recombination Velocity of Methylammonium-Free Mixed-Cation Mixed-Halide Perovskites via Surface Passivation

We control surface recombination in the mixed-cation, mixed-halide perovskite, FA0.83Cs0.17Pb(I0.85Br0.15)3, by passivating nonradiative defects with the polymerizable Lewis base (3-aminopropyl)trimethoxysilane (APTMS). We demonstrate average minority carrier lifetimes >4 µs, nearly single exponential monomolecular photoluminescence decays, and high external photoluminescence quantum efficiencies (>20%, corresponding to ~97% of the maximum theoretical quasi-Fermi-level splitting) at low excitation fluence. We confirm both the composition and valence band edge position of the FA0.83Cs0.17Pb(I0.85Br0.15)3 perovskite using multi-institutional, cross-validated, X-ray photoelectron spectroscopy and UV photoelectron spectroscopy measurements. We extend the APTMS surface passivation to higher bandgap double-cation (FA and Cs) compositions (1.7, 1.75, and 1.8 eV) as well as the widely used triple-cation (FA, MA, and Cs) composition. Finally, we demonstrate that the average surface recombination velocity decreases from ~1000 to ~10 cm/s post APTMS passivation for FA0.83Cs0.17Pb(I0.85Br0.15)3. Our results demonstrate that surface-mediated recombination is the primary nonradiative loss pathway in many methylammonium (MA)-free mixed-cation mixed-halide films with a range of different bandgaps, which is a problem observed for a wide range of perovskite active layers and reactive electrical contacts. Our study also provides insights to develop passivating molecules that help reduce surface recombination in MA-free mixed-cation mixed-halide films and indicates that surface passivation and contact engineering will enable near-theoretical device efficiencies with these materials.

14 SOLAR ENERGY↗
DOE OSTI2025

Data-Driven Mapping of the Cesium Cadmium Bromide Phase Space Utilizing a Soft-Chemistry Approach

Soft-chemistry techniques provide a versatile approach to synthesizing inorganic materials under mild conditions, enabling access to compositions and structures that are challenging to achieve through traditional thermodynamically driven solid-state methods. However, these solution-based routes often result in phase competition, requiring precise control over reaction conditions to achieve selective product formation. While one-variable-at-a-time (OVAT) approaches have traditionally been used for phase selection, data-driven strategies are emerging as more efficient methods for navigating complex synthetic spaces. Ternary metal halides, such as cesium cadmium bromides (Cs–Cd–Br), are of growing interest due to their potential in wide and ultrawide band gap applications. Unlike the well-studied cesium lead halide phases, the compositional diversity and solution-based synthesis of ternary Cs–Cd–Br phases remain largely unexplored. This study systematically investigates the synthetic phase space of the Cs–Cd–Br system by constructing a data-driven phase map. Using a common set of precursors and a standardized experimental procedure, we successfully synthesize all four known Cs–Cd–Br phases—CsCdBr 3 , Cs 2 CdBr 4 , Cs 3 CdBr 5 , and Cs 7 Cd 3 Br 13 —each exhibiting distinct structures, morphologies, and optical properties. Our findings highlight the potential of soft-chemistry methods for expanding the library of ternary metal halides and provide key insights into the thermodynamic and kinetic factors governing phase formation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Driving Force Dependent Photoinduced Charge Transfer Dynamics in Polymer-Wrapped Semiconducting Single-Walled Carbon Nanotubes

Here, we investigate the thermodynamic driving-force dependences of photoinduced charge separation (CS) and subsequent charge transfer dynamics in single-walled carbon nanotube (SWNT)–perylenediimide (PDI) donor–acceptor (D–A) superstructures. Pump–probe spectroscopy reveals that [SWNT (•+)n ]-(PDI –• ) n CS states form on an ∼100 fs time scale following photoexcitation; these dynamics are invariant across an ∼400 mV driving force range, indicating that SWNT hole polaron formation time scales are determined by nanotube lattice and solvent relaxation. These CS states feature SWNT hole polarons adjacent to (geminate) and nearby (nongeminate) PDI radical anions. Analysis of the free energy dependence for charge recombination (CR) of [SWNT •+ ] geminate -(PDI –• ) CS states highlights an ∼2 meV value for D–A electronic coupling (HAB) and ∼0.93 eV for the total reorganization energy (λ T ). A corresponding driving force dependence of the CR dynamics for [SWNT •+ ] nongeminate -(PDI –• ) CS states indicates a diminished H AB value (∼0.6 meV) and a larger λ T (∼1.1 eV), consistent with larger transfer distances. SWNT excitons that persist following photoinduced CS drive photooxidation of PDI –• components of [SWNT (•+)n ]-(PDI –• ) n CS states ( 1 SWNT* + PDI •– → PDI + SWNT •– ); this reaction manifests a significantly reduced λ T value (∼0.67 eV) as the initially prepared SWNT reduced state bears the character of a conduction band injected electron ([SWNT •– ] CB ). This reaction thus gives rise to relaxed, nongeminate SWNT electron and hole polarons on the same nanotube; these polarons react on a 10 2 ps time scale independent of the electronic structure of these SWNT-PDI superstructures.

anions↗
DOE OSTI2020

Discrepancy in the Critical State Void Ratio of Poorly Graded Sand due to Shear Strain Localization

The critical state (CS) concept is a theoretical framework that models the constitutive behavior of soils, including sand and other granular materials. It supports the notion of a unique postfailure state, where the soil ultimately experiences continuous shearing with no change in the plastic volumetric strain. However, the published literature has frequently noted the nonconvergence of sand specimens with different initial densities to a unique CS in the compression plane due to many factors such as specimen fabric, particle morphology, breakage, and grain size distribution. This paper examines the CS for poorly graded (uniform) glass beads and 3 different types of silica sands using 50 conventional triaxial compression (CTC) experiments, 12 oedometer tests, and in situ synchrotron microcomputed tomography (SMT) scans for 10 CTC experiments. The results of the 50 CTC experiments revealed a diffused CS zone in the compression plane, which was further examined using the in situ SMT scans. A thorough three-dimensional image analysis of the SMT scans accurately quantified the evolution of the local void ratio (elocal) versus axial compression within zones of intensive shearing toward the center of the specimen. The evolution of the void ratio was also measured using the entire volume of the specimen (eglobal). At the CS, the elocal/eglobal ratio was assessed to be ~1.25 when a single shear band developed within the scanned specimens and ~1.1-1.15 for specimens that failed via external bulging that was internally manifested by the development of multiple shear bands. This finding suggests that the CS zone in the compression plane can be attributed to the common wrong consideration of eglobal evolution in lieu of elocal within the developing shear bands. Furthermore, the lack of shear band development in uniaxial compression has made the results of the oedometer test reliable in quantifying the CS parameters in the compression plane.

58 GEOSCIENCES↗