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Materials Data on ScO2 by Materials Project

ScO2 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two ScO2 sheets oriented in the (0, 1, 0) direction. Sc is bonded to six O atoms to form a mixture of distorted corner and edge-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Sc–O bond distances ranging from 2.08–2.19 Å. There are two inequivalent O sites. In the first O site, O is bonded to four equivalent Sc atoms to form a mixture of distorted corner and edge-sharing OSc4 trigonal pyramids. In the second O site, O is bonded in a water-like geometry to two equivalent Sc atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScNi3 by Materials Project

ScNi3 is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Sc is bonded to twelve Ni atoms to form ScNi12 cuboctahedra that share corners with six equivalent ScNi12 cuboctahedra, corners with twelve NiSc4Ni8 cuboctahedra, edges with eighteen NiSc4Ni8 cuboctahedra, faces with eight equivalent ScNi12 cuboctahedra, and faces with twelve NiSc4Ni8 cuboctahedra. There are six shorter (2.65 Å) and six longer (2.66 Å) Sc–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Sc and eight Ni atoms to form distorted NiSc4Ni8 cuboctahedra that share corners with four equivalent ScNi12 cuboctahedra, corners with fourteen equivalent NiSc4Ni8 cuboctahedra, edges with six equivalent ScNi12 cuboctahedra, edges with twelve NiSc4Ni8 cuboctahedra, faces with four equivalent ScNi12 cuboctahedra, and faces with sixteen NiSc4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.51–2.79 Å. In the second Ni site, Ni is bonded to four equivalent Sc and eight equivalent Ni atoms to form distorted NiSc4Ni8 cuboctahedra that share corners with four equivalent ScNi12 cuboctahedra, corners with fourteen NiSc4Ni8 cuboctahedra, edges with six equivalent ScNi12 cuboctahedra, edges with twelve equivalent NiSc4Ni8 cuboctahedra, faces with four equivalent ScNi12 cuboctahedra, and faces with sixteen NiSc4Ni8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc4Ti3O12 by Materials Project

Sc4Ti3O12 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to seven O2- atoms to form distorted ScO7 pentagonal bipyramids that share a cornercorner with one TiO6 octahedra and an edgeedge with one TiO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Sc–O bond distances ranging from 2.09–2.33 Å. In the second Sc3+ site, Sc3+ is bonded in a 7-coordinate geometry to six O2- atoms. There are a spread of Sc–O bond distances ranging from 2.04–2.19 Å. In the third Sc3+ site, Sc3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sc–O bond distances ranging from 2.05–2.66 Å. In the fourth Sc3+ site, Sc3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Sc–O bond distances ranging from 2.05–2.44 Å. There are three inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one ScO7 pentagonal bipyramid and an edgeedge with one ScO7 pentagonal bipyramid. There are a spread of Ti–O bond distances ranging from 1.89–2.12 Å. In the second Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.93–2.13 Å. In the third Ti4+ site, Ti4+ is bonded in a 7-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.92–2.11 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ti4+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Sc3+ and two Ti4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Sc3+ and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Sc3+ and one Ti4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Sc3+ and one Ti4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Sc3+ and one Ti4+ atom. In the seventh O2- site, O2- is bonded to three Sc3+ and one Ti4+ atom to form OSc3Ti tetrahedra that share corners with five OSc2Ti2 tetrahedra, a cornercorner with one OSc2Ti2 trigonal pyramid, edges with two OSc3Ti tetrahedra, and an edgeedge with one OSc2Ti2 trigonal pyramid. In the eighth O2- site, O2- is bonded to two Sc3+ and two Ti4+ atoms to form OSc2Ti2 tetrahedra that share corners with five OSc3Ti tetrahedra, a cornercorner with one OSc2Ti2 trigonal pyramid, edges with two OSc3Ti tetrahedra, and an edgeedge with one OSc2Ti2 trigonal pyramid. In the ninth O2- site, O2- is bonded to three Sc3+ and one Ti4+ atom to form OSc3Ti tetrahedra that share corners with six OSc3Ti tetrahedra, edges with two OSc3Ti tetrahedra, and an edgeedge with one OSc2Ti2 trigonal pyramid. In the tenth O2- site, O2- is bonded to three Sc3+ and one Ti4+ atom to form distorted OSc3Ti tetrahedra that share corners with four OSc2Ti2 tetrahedra, corners with two equivalent OSc2Ti2 trigonal pyramids, and edges with three OSc3Ti tetrahedra. In the eleventh O2- site, O2- is bonded to three Sc3+ and one Ti4+ atom to form distorted OSc3Ti tetrahedra that share corners with four OSc3Ti tetrahedra, corners with two equivalent OSc2Ti2 trigonal pyramids, and edges with three OSc3Ti tetrahedra. In the twelfth O2- site, O2- is bonded to two Sc3+ and two Ti4+ atoms to form a mixture of distorted edge and corner-sharing OSc2Ti2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TbScSi2 by Materials Project

TbScSi2 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Tb is bonded in a 5-coordinate geometry to seven Si atoms. There are a spread of Tb–Si bond distances ranging from 2.88–3.08 Å. Sc is bonded in a 5-coordinate geometry to seven Si atoms. There are a spread of Sc–Si bond distances ranging from 2.88–3.04 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to three equivalent Tb, four equivalent Sc, and two equivalent Si atoms. Both Si–Si bond lengths are 2.47 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to four equivalent Tb, three equivalent Sc, and two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sc3RuC4 by Materials Project

Sc3RuC4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to eight C+3.50- atoms to form ScC8 hexagonal bipyramids that share corners with eight CSc5RuC pentagonal bipyramids and faces with two equivalent ScC8 hexagonal bipyramids. All Sc–C bond lengths are 2.42 Å. In the second Sc3+ site, Sc3+ is bonded to eight C+3.50- atoms to form ScC8 hexagonal bipyramids that share corners with eight CSc5RuC pentagonal bipyramids and faces with two equivalent ScC8 hexagonal bipyramids. There are four shorter (2.41 Å) and four longer (2.42 Å) Sc–C bond lengths. In the third Sc3+ site, Sc3+ is bonded in a 6-coordinate geometry to six C+3.50- atoms. There are four shorter (2.37 Å) and two longer (2.39 Å) Sc–C bond lengths. In the fourth Sc3+ site, Sc3+ is bonded in a 6-coordinate geometry to six C+3.50- atoms. There are a spread of Sc–C bond distances ranging from 2.36–2.39 Å. Ru5+ is bonded in a square co-planar geometry to four C+3.50- atoms. All Ru–C bond lengths are 2.22 Å. There are two inequivalent C+3.50- sites. In the first C+3.50- site, C+3.50- is bonded to five Sc3+, one Ru5+, and one C+3.50- atom to form distorted CSc5RuC pentagonal bipyramids that share corners with two ScC8 hexagonal bipyramids, corners with thirteen CSc5RuC pentagonal bipyramids, edges with five CSc5RuC pentagonal bipyramids, and faces with three CSc5RuC pentagonal bipyramids. The C–C bond length is 1.43 Å. In the second C+3.50- site, C+3.50- is bonded to five Sc3+, one Ru5+, and one C+3.50- atom to form distorted CSc5RuC pentagonal bipyramids that share corners with two ScC8 hexagonal bipyramids, corners with thirteen CSc5RuC pentagonal bipyramids, edges with five CSc5RuC pentagonal bipyramids, and faces with three CSc5RuC pentagonal bipyramids. The C–C bond length is 1.43 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScAg3 by Materials Project

ScAg3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Sc is bonded in a distorted body-centered cubic geometry to fourteen Ag atoms. There are eight shorter (2.91 Å) and six longer (3.36 Å) Sc–Ag bond lengths. There are two inequivalent Ag sites. In the first Ag site, Ag is bonded to four equivalent Sc and four equivalent Ag atoms to form a mixture of distorted corner, edge, and face-sharing AgSc4Ag4 tetrahedra. All Ag–Ag bond lengths are 2.91 Å. In the second Ag site, Ag is bonded in a 8-coordinate geometry to six equivalent Sc and eight equivalent Ag atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScO2 by Materials Project

ScO2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Sc is bonded to six O atoms to form a mixture of distorted edge and corner-sharing ScO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Sc–O bond distances ranging from 2.02–2.32 Å. There are two inequivalent O sites. In the first O site, O is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sc atoms. In the second O site, O is bonded in a trigonal planar geometry to three equivalent Sc atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScFe3 by Materials Project

ScFe3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Sc is bonded to twelve Fe atoms to form a mixture of corner and face-sharing ScFe12 cuboctahedra. There are six shorter (2.75 Å) and six longer (2.80 Å) Sc–Fe bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to four equivalent Sc and eight Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.44–3.05 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to four equivalent Sc and eight equivalent Fe atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScS2NO8 by Materials Project

(Sc(SO4)2)2N2 crystallizes in the trigonal P321 space group. The structure is two-dimensional and consists of one ammonia molecule and one Sc(SO4)2 sheet oriented in the (0, 0, 1) direction. In the Sc(SO4)2 sheet, Sc3+ is bonded to six equivalent O2- atoms to form distorted ScO6 octahedra that share corners with six equivalent SO4 tetrahedra. All Sc–O bond lengths are 2.11 Å. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with three equivalent ScO6 octahedra. The corner-sharing octahedral tilt angles are 34°. There is one shorter (1.45 Å) and three longer (1.50 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one S6+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Sc3+ and one S6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ScMnGe by Materials Project

ScMnGe crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Sc is bonded in a 5-coordinate geometry to five Ge atoms. There are one shorter (2.74 Å) and four longer (2.77 Å) Sc–Ge bond lengths. Mn is bonded to four Ge atoms to form a mixture of distorted edge and corner-sharing MnGe4 tetrahedra. There are two shorter (2.46 Å) and two longer (2.61 Å) Mn–Ge bond lengths. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 9-coordinate geometry to three equivalent Sc and six equivalent Mn atoms. In the second Ge site, Ge is bonded in a 9-coordinate geometry to six equivalent Sc and three equivalent Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy5Sc5(Si5Ir2)4 by Materials Project

Dy5Sc5(Ir2Si5)4 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are three inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded in a distorted q4 geometry to ten Si+2.80- atoms. There are a spread of Dy–Si bond distances ranging from 3.16–3.22 Å. In the second Dy3+ site, Dy3+ is bonded in a 10-coordinate geometry to ten Si+2.80- atoms. There are a spread of Dy–Si bond distances ranging from 3.15–3.23 Å. In the third Dy3+ site, Dy3+ is bonded to twelve Si+2.80- atoms to form distorted DySi12 cuboctahedra that share corners with eight IrSi5 trigonal bipyramids, edges with eight ScSi8 hexagonal bipyramids, faces with two equivalent DySi12 cuboctahedra, and faces with four IrSi5 trigonal bipyramids. There are a spread of Dy–Si bond distances ranging from 2.86–3.25 Å. There are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to eight Si+2.80- atoms to form distorted ScSi8 hexagonal bipyramids that share corners with four equivalent IrSi5 trigonal bipyramids, edges with four equivalent DySi12 cuboctahedra, faces with two equivalent ScSi8 hexagonal bipyramids, and faces with four equivalent IrSi5 trigonal bipyramids. There are a spread of Sc–Si bond distances ranging from 2.83–2.99 Å. In the second Sc3+ site, Sc3+ is bonded to eight Si+2.80- atoms to form distorted ScSi8 hexagonal bipyramids that share corners with four equivalent IrSi5 trigonal bipyramids, edges with four equivalent DySi12 cuboctahedra, faces with two equivalent ScSi8 hexagonal bipyramids, and faces with four equivalent IrSi5 trigonal bipyramids. There are a spread of Sc–Si bond distances ranging from 2.83–2.99 Å. In the third Sc3+ site, Sc3+ is bonded to eight Si+2.80- atoms to form distorted ScSi8 hexagonal bipyramids that share corners with four IrSi5 trigonal bipyramids, edges with four equivalent DySi12 cuboctahedra, faces with two equivalent ScSi8 hexagonal bipyramids, and faces with four IrSi5 trigonal bipyramids. There are a spread of Sc–Si bond distances ranging from 2.83–3.00 Å. In the fourth Sc3+ site, Sc3+ is bonded in a distorted q4 geometry to ten Si+2.80- atoms. There are a spread of Sc–Si bond distances ranging from 3.14–3.21 Å. There are four inequivalent Ir+3.25+ sites. In the first Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent DySi12 cuboctahedra, corners with two equivalent ScSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one DySi12 cuboctahedra, and faces with two equivalent ScSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.38–2.47 Å. In the second Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent DySi12 cuboctahedra, corners with two equivalent ScSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one DySi12 cuboctahedra, and faces with two equivalent ScSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.38–2.45 Å. In the third Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent DySi12 cuboctahedra, corners with two equivalent ScSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one DySi12 cuboctahedra, and faces with two equivalent ScSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.38–2.46 Å. In the fourth Ir+3.25+ site, Ir+3.25+ is bonded to five Si+2.80- atoms to form distorted IrSi5 trigonal bipyramids that share corners with two equivalent DySi12 cuboctahedra, corners with two equivalent ScSi8 hexagonal bipyramids, corners with five IrSi5 trigonal bipyramids, a faceface with one DySi12 cuboctahedra, and faces with two equivalent ScSi8 hexagonal bipyramids. There are a spread of Ir–Si bond distances ranging from 2.38–2.47 Å. There are eleven inequivalent Si+2.80- sites. In the first Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to four equivalent Dy3+, two equivalent Sc3+, two equivalent Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.36 Å. In the second Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to four equivalent Dy3+, two equivalent Sc3+, two equivalent Ir+3.25+, and one Si+2.80- atom. In the third Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Dy3+, four Sc3+, two Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.34 Å. In the fourth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, two equivalent Sc3+, two Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.39 Å. In the fifth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, two equivalent Sc3+, two Ir+3.25+, and one Si+2.80- atom. In the sixth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, two equivalent Sc3+, two Ir+3.25+, and one Si+2.80- atom. The Si–Si bond length is 2.39 Å. In the seventh Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to one Dy3+, four Sc3+, and two Ir+3.25+ atoms. In the eighth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to two equivalent Dy3+, two Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. There are one shorter (2.78 Å) and one longer (2.79 Å) Si–Si bond lengths. In the ninth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, one Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. Both Si–Si bond lengths are 2.78 Å. In the tenth Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, one Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms. In the eleventh Si+2.80- site, Si+2.80- is bonded in a 2-coordinate geometry to three Dy3+, one Sc3+, two equivalent Ir+3.25+, and two Si+2.80- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(ScS2)2 by Materials Project

Mg(ScS2)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one Mg(ScS2)2 sheet oriented in the (0, 0, 1) direction. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four S2- atoms to form MgS4 tetrahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent ScS6 octahedra, and corners with six ScS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–61°. There are one shorter (2.43 Å) and three longer (2.46 Å) Mg–S bond lengths. In the second Mg2+ site, Mg2+ is bonded to six S2- atoms to form MgS6 octahedra that share a cornercorner with one MgS4 tetrahedra, corners with five ScS4 tetrahedra, edges with two equivalent MgS6 octahedra, and edges with four equivalent ScS6 octahedra. There are a spread of Mg–S bond distances ranging from 2.64–2.70 Å. There are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to four S2- atoms to form ScS4 tetrahedra that share a cornercorner with one ScS6 octahedra, corners with two equivalent MgS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four ScS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–61°. There are a spread of Sc–S bond distances ranging from 2.42–2.47 Å. In the second Sc3+ site, Sc3+ is bonded to six S2- atoms to form ScS6 octahedra that share corners with two equivalent MgS4 tetrahedra, corners with four ScS4 tetrahedra, edges with two equivalent ScS6 octahedra, and edges with four equivalent MgS6 octahedra. There are a spread of Sc–S bond distances ranging from 2.58–2.68 Å. In the third Sc3+ site, Sc3+ is bonded to four S2- atoms to form ScS4 tetrahedra that share a cornercorner with one ScS6 octahedra, corners with two equivalent MgS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four ScS4 tetrahedra. The corner-sharing octahedra tilt angles range from 59–61°. There are a spread of Sc–S bond distances ranging from 2.42–2.48 Å. In the fourth Sc3+ site, Sc3+ is bonded to four S2- atoms to form ScS4 tetrahedra that share a cornercorner with one MgS6 octahedra, corners with two equivalent ScS6 octahedra, corners with two equivalent MgS4 tetrahedra, and corners with four ScS4 tetrahedra. The corner-sharing octahedral tilt angles are 60°. There are a spread of Sc–S bond distances ranging from 2.43–2.47 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Mg2+ and two Sc3+ atoms to form distorted SMg2Sc2 trigonal pyramids that share corners with five SMg2Sc2 tetrahedra, corners with four equivalent SMgSc3 trigonal pyramids, edges with two SMg2Sc2 tetrahedra, and an edgeedge with one SMg2Sc2 trigonal pyramid. In the second S2- site, S2- is bonded to two Mg2+ and two equivalent Sc3+ atoms to form distorted SMg2Sc2 tetrahedra that share corners with four equivalent SMg2Sc2 tetrahedra, corners with five SMg2Sc2 trigonal pyramids, an edgeedge with one SMg2Sc2 tetrahedra, and edges with two SMgSc3 trigonal pyramids. In the third S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Sc3+ atoms. In the fourth S2- site, S2- is bonded in a trigonal non-coplanar geometry to three Sc3+ atoms. In the fifth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Sc3+ atoms. In the sixth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Mg2+ and two Sc3+ atoms. In the seventh S2- site, S2- is bonded to one Mg2+ and three Sc3+ atoms to form distorted SMgSc3 trigonal pyramids that share corners with five SMg2Sc2 tetrahedra, corners with four equivalent SMg2Sc2 trigonal pyramids, edges with two SMg2Sc2 tetrahedra, and an edgeedge with one SMgSc3 trigonal pyramid. In the eighth S2- site, S2- is bonded to two equivalent Mg2+ and two Sc3+ atoms to form distorted SMg2Sc2 tetrahedra that share corners with four equivalent SMg2Sc2 tetrahedra, corners with five SMg2Sc2 trigonal pyramids, an edgeedge with one SMg2Sc2 tetrahedra, and edges with two SMgSc3 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg(ScSe2)2 by Materials Project

Mg(ScSe2)2 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 ScSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with four ScSe7 pentagonal bipyramids, an edgeedge with one MgSe6 octahedra, edges with four ScSe6 octahedra, and edges with three ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 15–56°. There are a spread of Mg–Se bond distances ranging from 2.66–2.80 Å. In the second Mg2+ site, Mg2+ is bonded to six Se2- atoms to form MgSe6 octahedra that share a cornercorner with one ScSe6 octahedra, corners with two equivalent MgSe6 octahedra, corners with four ScSe7 pentagonal bipyramids, an edgeedge with one MgSe6 octahedra, edges with four ScSe6 octahedra, and edges with three ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 15–56°. There are a spread of Mg–Se bond distances ranging from 2.68–2.75 Å. There are four inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to six Se2- atoms to form ScSe6 octahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent ScSe6 octahedra, corners with four ScSe7 pentagonal bipyramids, an edgeedge with one ScSe6 octahedra, edges with four MgSe6 octahedra, and edges with three ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–56°. There are a spread of Sc–Se bond distances ranging from 2.69–2.75 Å. In the second Sc3+ site, Sc3+ is bonded to six Se2- atoms to form ScSe6 octahedra that share a cornercorner with one MgSe6 octahedra, corners with two equivalent ScSe6 octahedra, corners with four ScSe7 pentagonal bipyramids, an edgeedge with one ScSe6 octahedra, edges with four MgSe6 octahedra, and edges with three ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–56°. There are a spread of Sc–Se bond distances ranging from 2.68–2.79 Å. In the third Sc3+ site, Sc3+ is bonded to seven Se2- atoms to form distorted ScSe7 pentagonal bipyramids that share corners with four MgSe6 octahedra, corners with four ScSe6 octahedra, edges with three MgSe6 octahedra, edges with three ScSe6 octahedra, and faces with two equivalent ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 18–67°. There are a spread of Sc–Se bond distances ranging from 2.71–2.99 Å. In the fourth Sc3+ site, Sc3+ is bonded to seven Se2- atoms to form distorted ScSe7 pentagonal bipyramids that share corners with four MgSe6 octahedra, corners with four ScSe6 octahedra, edges with three MgSe6 octahedra, edges with three ScSe6 octahedra, and faces with two equivalent ScSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 19–66°. There are a spread of Sc–Se bond distances ranging from 2.72–3.00 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two Mg2+ and three Sc3+ atoms to form distorted SeMg2Sc3 trigonal bipyramids that share corners with two equivalent SeMg2Sc3 square pyramids, corners with three equivalent SeMgSc3 tetrahedra, corners with two equivalent SeMg2Sc3 trigonal bipyramids, edges with three SeMg2Sc3 square pyramids, and edges with five SeMg2Sc3 trigonal bipyramids. In the second Se2- site, Se2- is bonded to two Mg2+ and three Sc3+ atoms to form distorted SeMg2Sc3 trigonal bipyramids that share corners with six SeMg2Sc3 square pyramids, corners with two equivalent SeMgSc3 tetrahedra, corners with two equivalent SeMg2Sc3 trigonal bipyramids, an edgeedge with one SeMg2Sc3 square pyramid, an edgeedge with one SeMgSc3 tetrahedra, and edges with five SeMg2Sc3 trigonal bipyramids. In the third Se2- site, Se2- is bonded to one Mg2+ and three Sc3+ atoms to form distorted SeMgSc3 tetrahedra that share corners with two SeMg2Sc3 square pyramids, corners with ten SeMg2Sc3 trigonal bipyramids, edges with two SeMg2Sc3 square pyramids, and edges with two SeMgSc4 trigonal bipyramids. In the fourth Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Sc3+ atoms. In the fifth Se2- site, Se2- is bonded to two Mg2+ and three Sc3+ atoms to form distorted SeMg2Sc3 square pyramids that share a cornercorner with one SeMgSc3 tetrahedra, corners with eight SeMg2Sc3 trigonal bipyramids, edges with two equivalent SeMg2Sc3 square pyramids, an edgeedge with one SeMgSc3 tetrahedra, and edges with four SeMg2Sc3 trigonal bipyramids. In the sixth Se2- site, Se2- is bonded to two Mg2+ and three Sc3+ atoms to form distorted SeMg2Sc3 square pyramids that share a cornercorner with one SeMgSc3 tetrahedra, corners with eight SeMg2Sc3 trigonal bipyramids, edges with two equivalent SeMg2Sc3 square pyramids, an edgeedge with one SeMgSc3 tetrahedra, and edges with four SeMg2Sc3 trigonal bipyramids. In the seventh Se2- site, Se2- is bonded to one Mg2+ and four Sc3+ atoms to form distorted SeMgSc4 trigonal bipyramids that share corners with two equivalent SeMg2Sc3 square pyramids, corners with two equivalent SeMgSc3 tetrahedra, corners with two equivalent SeMgSc4 trigonal bipyramids, edges with three SeMg2Sc3 square pyramids, an edgeedge with one SeMgSc3 tetrahedra, and edges with five SeMg2Sc3 trigonal bipyramids. In the eighth Se2- site, Se2- is bonded to one Mg2+ and four Sc3+ atoms to form distorted SeMgSc4 trigonal bipyramids that share corners with six SeMg2Sc3 square pyramids, corners with three equivalent SeMgSc3 tetrahedra, corners with two equivalent SeMgSc4 trigonal bipyramids, an edgeedge with one SeMg2Sc3 square pyramid, and edges with five SeMg2Sc3 trigonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Proximity Ferroelectricity in Compositionally Graded Structures

Proximity ferroelectricity is a novel paradigm for inducing ferroelectricity in a non-ferroelectric polar material, such as AlN or ZnO that are typically unswitchable with an external field below their dielectric breakdown field. When placed in direct contact with a thin switchable ferroelectric layer (such as Al 1-x Sc x N or Zn 1-x Mg x O), they become a practically switchable ferroelectric. Using the thermodynamic Landau-Ginzburg-Devonshire theory, in this work, we perform the finite element modeling of the polarization switching in the compositionally graded AlN-Al 1-x Sc x N, ZnO-Zn 1-x Mg x O, and MgO-Zn 1-x Mg x O structures sandwiched in both a parallel-plate capacitor geometry as well as in a sharp probe-planar electrode geometry. We reveal that the compositionally graded structure allows the simultaneous switching of spontaneous polarization in the whole system by a coercive field significantly lower than the electric breakdown field of unswitchable polar materials. The physical mechanism is the depolarization electric field determined by the gradient of chemical composition “x”. The field lowers the steepness of the switching barrier in the otherwise unswitchable parts of the compositionally graded AlN-Al 1-x Sc x N and ZnO-Zn 1-x Mg x O structures. In the MgO-like regions of the compositionally graded MgO-Zn 1-x Mg x O structure, a shallow double-well free energy potential emerges. Proximity ferroelectric switching of the compositionally graded structures placed in the probe-electrode geometry occurs due to nanodomain formation under the tip. We predict that a gradient of chemical composition “x” significantly lowers effective coercive fields of the compositionally graded AlN-Al 1-x Sc x N and ZnO-Zn 1-x Mg x O structures compared to the coercive fields of the corresponding multilayers with a uniform chemical composition in each layer. A tip-induced switching further lowers the coercive field, enabling control of ferroelectric domains in otherwise unswitchable compositionally graded structures, which can provide nanoscale domain control for memory, actuation, sensing, and optical applications.

36 MATERIALS SCIENCE↗
DOE OSTI2022

In‐Silico Device Performance Prediction of Cosensitizer Dye Pairs for Dye‐Sensitized Solar Cells

Abstract Endeavors in the field of dye‐sensitized solar cells (DSCs) have shown great promise when adopting a data‐driven approach to materials discovery, such as successful molecular‐scale predictions of light‐harvesting chromophores. However, predictions of DSC dyes would become much more sophisticated if a molecular‐to‐macroscopic DSC device prediction methodology existed. Thereby, a fully computational pipeline is presented that predicts device‐performance parameters of DSCs which contain varying dye combinations. Optimal pairing of complementary dyes is identified via a data‐driven workflow that affords cosensitized DSCs with maximum power‐conversion efficiencies. Six high‐performing DSC dyes are paired with partner dyes that are screened from a database of 8488 compounds using sequential heuristic filters. Existing models that predict short‐circuit‐current density ( J SC ) and open‐circuit voltage ( V OC ) parameters are adapted to predict singly sensitized and cosensitized DSC performance. The predictions for J sc values of singly sensitized devices match experimental literature values with comparable accuracy to more computationally costly methods. Five out of six dye pairings are predicted to have greater J SC values when cosensitized compared to their corresponding singly sensitized devices, including two pairs that show strong J sc boosts of +13% and +12% when cosensitized. Thus, the prospect of an entirely in‐silico prediction pipeline for DSC performance that can be used to realize the fully automated design of optimized cosensitized DSCs is demonstrated.

14 SOLAR ENERGY↗
DOE OSTI2022

An Anomalous Electron Configuration Among 3d Transition Metal Atoms

Physical properties of materials are mainly determined by valence electron configurations, where different valence shells would induce divergent phenomena. In compounds containing Sc 2+ , 3d electron occupancy is expected, same as other transition metal atoms like Ti 3+ . But this situation still awaits experimental verification. In this work, we selected ScS to measure the valence electron density and orbital population of Sc2+ through delicate quantitative convergent-beam electron diffraction. Though the [Ar]3d 1 configuration is confirmed in ionic Sc 2+ , the unintuitive occupation of 4s orbital is concluded with the absence of 3d orbital features around Sc-atom sites and nearly bare population of t2g orbital. It should be the first time to report this special electron configuration in a transition metal compound, in which 4s rather than 3d orbital is preferred. Our findings reveal the distinct behavior of Sc, and probable ways to modulate material properties by controlling electron orbitals.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Measurement of distribution coefficients on TODGA resin and development of a group separation for mixed activation and fission product samples

Batch equilibrium experiments were performed to determine the distribution coefficients for Sc, Ir, and Ta on N,N,N’,N’tetraoctyl-1,5-diglycolamide (TODGA) resin in various acid matrices. Distribution coefficients were determined in hydrochloric acid (Sc, Ir), nitric acid (Sc, Ta), and a mixture of nitric acid and 0.2M hydrofluoric acid (Sc, Ir, Ta). The distribution coefficients determined through these experiments were then utilized to create a group separation method for activation products, fission products, and environmental constituents.

Louie, Christina A.↗
DOE OSTI2021

Branching ratios for the three most intense gamma rays in the decay of 47 Ca

A sample of 47 Ca produced through isotope harvesting at the National Superconducting Cyclotron Laboratory was used to measure branching ratios of 7.17(5)%, 7.11(5)%, and 75.0(5)% for the 489.2, 807.9, and 1297.1 keV characteristic gamma rays, respectively. Based on these updated branching ratios, the ground state to ground state 47 Ca to 47 Sc beta decay branching ratio has been indirectly measured as 17.7(5)% and the ground state to 1297.1 keV excited state as 82.2(5)%. Here these values represent a greatly increased precision for all five branching ratios compared to the currently accepted values. The measurements presented here were made relative to the ingrown 47Sc daughter in a 47 Ca sample and the well-established 159.4 keV gamma-ray branching ratio and the half-life for the decay of 47 Sc. These measurements were supported by verifying that the half-lives measured from characteristic gamma-ray peaks over multiple spectra for both 47 Ca and 47 Sc were consistent with previously reported values. Additionally, the half-lives of both 47 Ca and 47 Sc were independently measured with Liquid Scintillation Counting to reverify the previously reported values used in this study to find updated gamma-ray branching ratio values.

07 ISOTOPE AND RADIATION SOURCES↗