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DOE OSTI2020

Materials Data on Sr12Al14O33 by Materials Project

Sr12Al14O33 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are eight inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 square pyramids that share corners with six AlO4 tetrahedra and a cornercorner with one SrO5 trigonal bipyramid. There are a spread of Sr–O bond distances ranging from 2.27–2.63 Å. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.43–2.68 Å. In the third Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.43–2.68 Å. In the fourth Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.48–2.64 Å. In the fifth Sr2+ site, Sr2+ is bonded to five O2- atoms to form distorted SrO5 trigonal bipyramids that share a cornercorner with one SrO5 square pyramid and corners with six AlO4 tetrahedra. There are a spread of Sr–O bond distances ranging from 2.27–2.63 Å. In the sixth Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.48–2.64 Å. In the seventh Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.62 Å. In the eighth Sr2+ site, Sr2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.62 Å. There are eight inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. All Al–O bond lengths are 1.77 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There is two shorter (1.77 Å) and two longer (1.78 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one SrO5 square pyramid and corners with four AlO4 tetrahedra. There is one shorter (1.77 Å) and three longer (1.78 Å) Al–O bond length. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three AlO4 tetrahedra and a cornercorner with one SrO5 trigonal bipyramid. There is one shorter (1.73 Å) and three longer (1.80 Å) Al–O bond length. In the fifth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three AlO4 tetrahedra and a cornercorner with one SrO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.75–1.81 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO4 tetrahedra and a cornercorner with one SrO5 trigonal bipyramid. There is one shorter (1.77 Å) and three longer (1.78 Å) Al–O bond length. In the seventh Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one SrO5 square pyramid and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.81 Å. In the eighth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one SrO5 square pyramid and corners with three AlO4 tetrahedra. There is one shorter (1.73 Å) and three longer (1.80 Å) Al–O bond length. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with two OSr2Al2 trigonal pyramids. In the second O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with three OSr2Al2 trigonal pyramids. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two Al3+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and two Al3+ atoms. In the fifth O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and an edgeedge with one OSr2Al2 trigonal pyramid. In the sixth O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with three OSr2Al2 trigonal pyramids. In the seventh O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with two OSr2Al2 trigonal pyramids. In the eighth O2- site, O2- is bonded to three Sr2+ and one Al3+ atom to form distorted OSr3Al tetrahedra that share corners with three OSr3Al tetrahedra, corners with eight OSr2Al2 trigonal pyramids, and an edgeedge with one OSr2Al2 trigonal pyramid. In the ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Sr2+ and two Al3+ atoms. In the tenth O2- site, O2- is bonded to three Sr2+ and one Al3+ atom to form distorted OSr3Al tetrahedra that share corners with three OSr3Al tetrahedra, corners with four OSr2Al2 trigonal pyramids, and edges with three OSr2Al2 trigonal pyramids. In the eleventh O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with three OSr2Al2 trigonal pyramids. In the twelfth O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and an edgeedge with one OSr2Al2 trigonal pyramid. In the thirteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Sr2+ and two Al3+ atoms. In the fourteenth O2- site, O2- is bonded to three Sr2+ and one Al3+ atom to form distorted OSr3Al tetrahedra that share corners with three OSr3Al tetrahedra, corners with eight OSr2Al2 trigonal pyramids, and an edgeedge with one OSr2Al2 trigonal pyramid. In the fifteenth O2- site, O2- is bonded to two Sr2+ and two Al3+ atoms to form distorted OSr2Al2 trigonal pyramids that share corners with three OSr3Al tetrahedra, corners with three OSr2Al2 trigonal pyramids, an edgeedge with one OSr3Al tetrahedra, and edges with three OSr2Al2 trigonal pyramids. In the sixteenth O2- site, O2- is bonded to three Sr2+ and one Al3+ atom to form distorted OSr3Al tetrahedra that share corners with three OSr3Al tetrahedra, corners with four OSr2Al2 trigonal pyramids, and edges with three OSr2Al2 trigonal pyramids. In the seventeenth O2- site, O2- is bonded in a linear geometry to two Sr2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on BaSr11Al4(O4F)4 by Materials Project

BaSr11Al4(O4F)4 crystallizes in the tetragonal P422 space group. The structure is three-dimensional. Ba2+ is bonded in a distorted q6 geometry to eight equivalent O2- and two equivalent F1- atoms. All Ba–O bond lengths are 2.93 Å. Both Ba–F bond lengths are 2.87 Å. There are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to six O2- and two F1- atoms. There are a spread of Sr–O bond distances ranging from 2.48–2.74 Å. There are one shorter (2.55 Å) and one longer (2.56 Å) Sr–F bond lengths. In the second Sr2+ site, Sr2+ is bonded in a distorted q6 geometry to eight equivalent O2- and two equivalent F1- atoms. All Sr–O bond lengths are 2.89 Å. Both Sr–F bond lengths are 2.82 Å. In the third Sr2+ site, Sr2+ is bonded in a distorted q6 geometry to eight equivalent O2- and two equivalent F1- atoms. All Sr–O bond lengths are 2.87 Å. Both Sr–F bond lengths are 2.83 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to eight equivalent O2- and two equivalent F1- atoms. All Sr–O bond lengths are 2.89 Å. Both Sr–F bond lengths are 2.77 Å. There are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Al–O bond lengths are 1.80 Å. In the second Al3+ site, Al3+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Al–O bond lengths are 1.80 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to one Ba2+, four Sr2+, and one Al3+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to five Sr2+ and one Al3+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to one Ba2+ and five Sr2+ atoms to form corner-sharing FBaSr5 octahedra. The corner-sharing octahedra tilt angles range from 0–36°. In the second F1- site, F1- is bonded to six Sr2+ atoms to form corner-sharing FSr6 octahedra. The corner-sharing octahedra tilt angles range from 0–36°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrAl(OF2)2 by Materials Project

SrAl(OF2)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sr is bonded in a 9-coordinate geometry to two equivalent O and seven F atoms. There are one shorter (2.76 Å) and one longer (2.84 Å) Sr–O bond lengths. There are a spread of Sr–F bond distances ranging from 2.46–2.70 Å. Al is bonded to two equivalent O and four F atoms to form edge-sharing AlO2F4 octahedra. There is one shorter (1.95 Å) and one longer (1.98 Å) Al–O bond length. There are a spread of Al–F bond distances ranging from 1.75–1.82 Å. There are two inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to two equivalent Al atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two equivalent Sr atoms. There are four inequivalent F sites. In the first F site, F is bonded in a 1-coordinate geometry to two equivalent Sr and one Al atom. In the second F site, F is bonded in a distorted bent 150 degrees geometry to one Sr and one Al atom. In the third F site, F is bonded in a 1-coordinate geometry to two equivalent Sr and one Al atom. In the fourth F site, F is bonded in a 1-coordinate geometry to two equivalent Sr and one Al atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2Mg by Materials Project

Sr2Mg1 is Khatyrkite structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 4-coordinate geometry to four equivalent Mg atoms. There are a spread of Sr–Mg bond distances ranging from 3.71–3.76 Å. In the second Sr site, Sr is bonded in a 4-coordinate geometry to four equivalent Mg atoms. There are two shorter (3.69 Å) and two longer (3.73 Å) Sr–Mg bond lengths. Mg is bonded in a 10-coordinate geometry to eight Sr and two equivalent Mg atoms. There are one shorter (3.38 Å) and one longer (3.39 Å) Mg–Mg bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr3Hg by Materials Project

Sr3Hg is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is two-dimensional and consists of two Sr3Hg sheets oriented in the (0, 0, 1) direction. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a distorted water-like geometry to two equivalent Hg atoms. There are one shorter (3.37 Å) and one longer (3.41 Å) Sr–Hg bond lengths. In the second Sr site, Sr is bonded in a bent 150 degrees geometry to two equivalent Hg atoms. There are one shorter (3.28 Å) and one longer (3.32 Å) Sr–Hg bond lengths. Hg is bonded in a 6-coordinate geometry to six Sr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2Mg by Materials Project

Sr2Mg1 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two Sr2Mg1 sheets oriented in the (1, 0, 0) direction. there are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a 4-coordinate geometry to four equivalent Mg atoms. All Sr–Mg bond lengths are 3.63 Å. In the second Sr site, Sr is bonded in a 4-coordinate geometry to four equivalent Mg atoms. All Sr–Mg bond lengths are 3.62 Å. Mg is bonded in a body-centered cubic geometry to eight Sr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr8V6O19 by Materials Project

Sr8V6O19 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are eight inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, faces with six VO6 octahedra, and faces with two equivalent VO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.77–2.84 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, faces with six VO6 octahedra, and faces with two equivalent VO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.78–2.84 Å. In the third Sr2+ site, Sr2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.78 Å. In the fourth Sr2+ site, Sr2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.66–2.79 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.53–2.80 Å. In the sixth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.41–2.80 Å. In the seventh Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–2.81 Å. In the eighth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.45–2.80 Å. There are six inequivalent V+3.67+ sites. In the first V+3.67+ site, V+3.67+ is bonded to six O2- atoms to form VO6 octahedra that share a cornercorner with one VO6 octahedra and corners with four equivalent VO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There is five shorter (1.98 Å) and one longer (1.99 Å) V–O bond length. In the second V+3.67+ site, V+3.67+ is bonded to five O2- atoms to form corner-sharing VO5 square pyramids. The corner-sharing octahedral tilt angles are 10°. There is one shorter (1.96 Å) and four longer (1.99 Å) V–O bond length. In the third V+3.67+ site, V+3.67+ is bonded to six O2- atoms to form VO6 octahedra that share corners with four equivalent VO6 octahedra, a cornercorner with one VO5 square pyramid, and faces with four SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of V–O bond distances ranging from 1.89–2.00 Å. In the fourth V+3.67+ site, V+3.67+ is bonded to six O2- atoms to form VO6 octahedra that share corners with five VO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of V–O bond distances ranging from 1.94–2.10 Å. In the fifth V+3.67+ site, V+3.67+ is bonded to five O2- atoms to form VO5 square pyramids that share corners with five VO6 octahedra and faces with four SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–9°. There is one shorter (1.91 Å) and four longer (1.95 Å) V–O bond length. In the sixth V+3.67+ site, V+3.67+ is bonded to six O2- atoms to form VO6 octahedra that share corners with two VO6 octahedra, corners with four equivalent VO5 square pyramids, and faces with four SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of V–O bond distances ranging from 1.87–2.01 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to five Sr2+ and one V+3.67+ atom to form distorted OSr5V octahedra that share corners with twelve OSr4V2 octahedra, edges with eight OSr5V octahedra, and faces with four equivalent OSr4V2 octahedra. The corner-sharing octahedra tilt angles range from 6–57°. In the second O2- site, O2- is bonded to five Sr2+ and one V+3.67+ atom to form distorted OSr5V octahedra that share corners with twelve OSr4V2 octahedra, edges with eight OSr5V octahedra, and faces with four equivalent OSr4V2 octahedra. The corner-sharing octahedra tilt angles range from 12–55°. In the third O2- site, O2- is bonded to five Sr2+ and one V+3.67+ atom to form distorted OSr5V octahedra that share corners with eight OSr4V2 octahedra and edges with eight OSr5V octahedra. The corner-sharing octahedra tilt angles range from 8–46°. In the fourth O2- site, O2- is bonded to five Sr2+ and one V+3.67+ atom to form distorted OSr5V octahedra that share corners with eight OSr4V2 octahedra and edges with eight OSr5V octahedra. The corner-sharing octahedra tilt angles range from 10–46°. In the fifth O2- site, O2- is bonded to four Sr2+ and two V+3.67+ atoms to form a mixture of distorted edge, face, and corner-sharing OSr4V2 octahedra. The corner-sharing octahedra tilt angles range from 5–57°. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two V+3.67+ atoms. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two V+3.67+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two V+3.67+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two V+3.67+ atoms. In the tenth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+ and two V+3.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2Fe(PO4)3 by Materials Project

Sr2Fe(PO4)3 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Sr is bonded in a 8-coordinate geometry to eight O atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.92 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.05 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 27°. There is two shorter (1.54 Å) and two longer (1.55 Å) P–O bond length. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra. The corner-sharing octahedra tilt angles range from 38–44°. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. There are six inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to one Sr, one Fe, and one P atom. In the second O site, O is bonded in a distorted bent 120 degrees geometry to one Sr and one P atom. In the third O site, O is bonded in a 1-coordinate geometry to three equivalent Sr and one P atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Sr and one P atom. In the fifth O site, O is bonded in a 2-coordinate geometry to one Sr, one Fe, and one P atom. In the sixth O site, O is bonded in a 3-coordinate geometry to one Sr, one Fe, and one P atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr2LiN by Materials Project

LiSr2N crystallizes in the tetragonal I4mm space group. The structure is two-dimensional and consists of two LiSr2N sheets oriented in the (0, 0, 1) direction. Li is bonded in a single-bond geometry to one N atom. The Li–N bond length is 1.97 Å. There are two inequivalent Sr sites. In the first Sr site, Sr is bonded in a single-bond geometry to one N atom. The Sr–N bond length is 2.41 Å. In the second Sr site, Sr is bonded in a rectangular see-saw-like geometry to four equivalent N atoms. All Sr–N bond lengths are 2.78 Å. N is bonded to one Li and five Sr atoms to form a mixture of distorted edge and corner-sharing NSr5Li octahedra. The corner-sharing octahedral tilt angles are 7°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr4Nb2O9 by Materials Project

Sr4Nb2O9 is Pb (Zr_0.50 Ti_0.48) O_3-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.39–3.22 Å. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.32–2.77 Å. In the third Sr2+ site, Sr2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sr–O bond distances ranging from 2.44–2.60 Å. In the fourth Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.31–3.11 Å. In the fifth Sr2+ site, Sr2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Sr–O bond distances ranging from 2.64–3.22 Å. In the sixth Sr2+ site, Sr2+ is bonded to seven O2- atoms to form distorted SrO7 pentagonal bipyramids that share corners with three equivalent NbO6 octahedra, corners with two equivalent NbO6 pentagonal pyramids, and an edgeedge with one NbO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 17–33°. There are a spread of Sr–O bond distances ranging from 2.41–2.82 Å. In the seventh Sr2+ site, Sr2+ is bonded in a 1-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.35–3.13 Å. In the eighth Sr2+ site, Sr2+ is bonded in a 12-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.62–3.00 Å. There are four inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 16–17°. There are a spread of Nb–O bond distances ranging from 1.88–2.23 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form distorted NbO6 pentagonal pyramids that share corners with two equivalent SrO7 pentagonal bipyramids and an edgeedge with one SrO7 pentagonal bipyramid. There are a spread of Nb–O bond distances ranging from 2.00–2.09 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with three equivalent NbO6 octahedra and corners with three equivalent SrO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 13–18°. There are a spread of Nb–O bond distances ranging from 1.90–2.21 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 13–18°. There are a spread of Nb–O bond distances ranging from 2.00–2.07 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to five Sr2+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to five Sr2+ and one Nb5+ atom. In the third O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form a mixture of distorted edge and corner-sharing OSr3Nb trigonal pyramids. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Nb5+ atom. In the fifth O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form a mixture of distorted edge and corner-sharing OSr3Nb tetrahedra. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the seventh O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form a mixture of distorted edge and corner-sharing OSr3Nb trigonal pyramids. In the eighth O2- site, O2- is bonded to three Sr2+ and one Nb5+ atom to form a mixture of distorted edge and corner-sharing OSr3Nb trigonal pyramids. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Nb5+ atom. In the twelfth O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and one Nb5+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to four Sr2+ and one Nb5+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and two Nb5+ atoms. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Sr2+ and two Nb5+ atoms. In the seventeenth O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and two Nb5+ atoms. In the eighteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Sr2+ and two Nb5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2025

A general framework for nitrogen deposition effects on soil respiration in global forests

Since the Industrial Revolution, human activities have altered atmospheric nitrogen (N) deposition to global forests, affecting carbon dioxide emissions from soils (soil respiration or SR) – one of the largest land-atmosphere carbon fluxes. However, experimental studies have demonstrated both positive and negative effects of N deposition on SR in global forests, leading to debates on how N deposition increases or decreases SR. We developed a framework for generalizing SR responses to N deposition using synthesized data from 168 N addition experiments worldwide and observed SR across the global natural N deposition gradient. The findings indicate that N deposition decreased SR in 2.9% of global forested areas, particularly in eastern China, western Europe, and the eastern USA. However, the net effect of N deposition increased the global forest SR by ~5% (1.7 ± 0.1 PgC yr –1 ). If N pollution could be effectively controlled, global forest SR would decrease, potentially contributing to a reduction in the terrestrial carbon emissions.

Cen, Xiaoyu [National Forestry and Grassland Admin↗
DOE OSTI2021

Sulfur Poisoning and Performance Recovery of SOFC Air Electrodes

The sulfur poisoning and performance recovery of the state-of-the-art SOFC cathodes (La 0 . 80 Sr 0 . 20 ) 0 . 95 MnO 3 ± δ (LSM) and (La 0 . 60 Sr 0 . 40 ) 0 . 95 Co 0 . 20 Fe 0 . 80 O 3 – δ (LSCF), have been studied. Electrochemical impedance spectroscopy measurements of LSCF|GDC and LSM|YSZ half-cells are carried out in alternating atmospheres of air and SO 2 –air at 700°C for hundreds of hours. In the presence of SO 2 , the electrochemical performance of both the cells decays with ohmic and non-ohmic losses, owing to the absorption and chemical interaction of SO 2 with the electrodes. In LSCF, the SrO segregated on the surface tends to absorb and react with SO 2 , forming SrSO 4 followed by the exsolution of Co-Fe. As for LSM, SO 2 is absorbed onto the Sr-rich areas of LSM, including the active reaction sites near the TPBs, leading to Sr exsolution and SrSO 4 formation, leaving a Sr-deficient LSM. During the subsequent exposure to air, the performance of the sulfur-contaminated LSM is almost restored. The LSM particles, exposed to alternating atmospheres of air and SO 2 -air during the electrochemical tests, show a relatively clean surface with sparsely distributed SrSO 4 particles, indicating a high stability against sulfur poisoning. It is suggested that the loosely adsorbed SO 2 at the TPBs is readily swept away by the SO 2 -free air flow, recovering its ORR activity, whereas the Sr-deficient LSM due to Sr-exsolution stays modified, contributing to the incomplete performance restoration. Unlike the case of LSM, the performance of the sulfur-poisoned LSCF partially recovers during the subsequent exposure to air. Correspondingly, the LSCF particles have a modified morphology covered with numerous nanoparticles, mostly SrSO 4 , showing the irreversible aspect of the sulfur poisoning. The morphology modification is not concentrated near the electrode/electrolyte interface but over the entire cathode, indicating that the degree of recovery from sulfur poisoning is closely related to the presence of SrO and chemical activity of Sr in the electrodes at the solid-gas interface. These results also show the potential application of LSM for a sulfur sensor available in high-temperature harsh conditions.

25 ENERGY STORAGE↗
NASA NTRS1994

Neodymium, strontium and chromium isotopic studies of the LEW86010 and Angra dos Reis meteorites and the chronology of the angrite parent body

Neodymium, stontium, and chromium isotopic studies of the LEW86010 angrite established its absolute age and the formation interval between its crystallization and condensation of Allende CAIs from the solar nebula. Pyroxene and phosphate were found to contain approximately 8% of its Sm and Nd inventory. A conventional Sm-147-Nd-143 isochron yielded an age of 4.53 +/- 0.04 Ga (2 sigma and Epsilon(sub Nd sup 143)) = 0.45 +/- 1.1. An Sm-146-Nd-142 isochron gives initial Sm-146/Sm-144 = 0.0076 +/- 0.0009 and Epsilon (sub Nd sup 142) = -2.5 +/- 0.4. The Rb-Sr analyses give initial Sr-87/Sr-86 Iota(sub Sr sup 87) = 0.698972 +/- 8 and 0.698970 +/- 18 for LEW and ADOR, respectively, relative to Sr-87/Sr-86 = 0.71025 for NBS987. The difference, Delta Iota(sub Sr Sup 87), between Iota (sub sr sup 87) for the angrites and literature values for Allende CAIs, corresponds to approximately Ma of growth in a solar nebula with a CI chondrite value of Rb-87/Sr-86 = 0.91, or approximately 5 Ma in a nebula with solar photospheric Rb-87/Sr-86 = 1.51. Excess Cr-53 from extinct Mn-53(t(sub 1/2) = 3.7 Ma)in LEW86010 corresponds to initial Mn-53/Mn-55 = 4.4 +/- 1.0 x 10(exp -5) for the inclusions as previously reported by the Paris group (Birck and Allegre, 1988). The Sm-146/Sm-144 value found for LEW86010 corresponds to solar system initial (Sm-146/Sm-144) = 0.0080 +/- 0.0009 for crystallization 8 Ma after Allende, the difference between Pb-Pb ages of angrites and Allende, or 0.0086 +/- 0.0009 for crystallation 18 Ma after Allende, using the Mn-Cr formation interval. The isotopic data are discussed in the context of a model in which an undifferentiated 'chondritic' parent body formed from the solar nebula approximately Ma after Allende CAIs and subsequently underwent differentiation accompanied by loss of volatiles. Parent bodies with Rb/Sr similar to that of CI, CM, or CO chondrites could satisfy the Cr and Sr isotopic systematics. If the angrite parent body had Rb/Sr similar to that of CV meteorites, it would have to form slightly later, approximately 2.6 Ma after the CAIs, to satisfy the Sr and CR isotopic systematics.

Nyquist, L. E.↗
NASA NTRS2010

Extinction-to-Backscatter Ratios of Saharan Dust Layers Derived from In-Situ Measurements and CALIPSO Overflights During NAMMA

We determine the extinction-to-backscatter (Sa) ratios of dust using (1) airborne in-situ measurements of microphysical properties, (2) modeling studies, and (3) the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) observations recorded during the NASA African Monsoon Multidisciplinary Analyses (NAMMA) field experiment conducted from Sal, Cape Verde during Aug-Sept 2006. Using CALIPSO measurements of the attenuated backscatter of lofted Saharan dust layers, we apply the transmittance technique to estimate dust Sa ratios at 532 nm and a 2-color method to determine the corresponding 1064 nm Sa. This method yielded dust Sa ratios of 39.8 plus or minus 1.4 sr and 51.8 plus or minus 3.6 sr at 532 nm and 1064 nm, respectively. Secondly, Sa at both wavelengths is independently calculated using size distributions measured aboard the NASA DC-8 and estimates of Saharan dust complex refractive indices applied in a T-Matrix scheme. We found Sa ratios of 39.1 plus or minus 3.5 sr and 50.0 plus or minus 4 sr at 532 nm and 1064 nm, respectively, using the T-Matrix calculations applied to measured size spectra. Finally, in situ measurements of the total scattering (550 nm) and absorption coefficients (532 nm) are used to generate an extinction profile that is used to constrain the CALIPSO 532 nm extinction profile and thus generate a stratified 532 nm Sa. This method yielded an Sa ratio at 532 nm of 35.7 sr in the dust layer and 25 sr in the marine boundary layer consistent with a predominantly seasalt aerosol near the ocean surface. Combinatorial simulations using noisy size spectra and refractive indices were used to estimate the mean and uncertainty (one standard deviation) of these Sa ratios. These simulations produced a mean (plus or minus uncertainty) of 39.4 (plus or minus 5.9) sr and 56.5 (plus or minus 16.5) sr at 532 nm and 1064 nm, respectively, corresponding to percent uncertainties of 15% and 29%. These results will provide a measurements-based estimate of the dust Sa for use in backscatter lidar inversion algorithms such as CALIOP.

Omar, Ali H.↗
NASA NTRS2016

Exhibition of Stochastic Resonance in Vestibular Perception

Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 μA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 μA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz (OTO) with SVS up to 700 μA. A sinusoidal galvanic vestibular stimulation (GVS) perceptual threshold was also measured on each test day and used to normalize the SVS levels across subjects. In roll-tilt thresholds with SVS, the characteristic SR curve was qualitatively exhibited in 10 of 12 subjects, and the improvement in motion threshold was significant in 6 subjects, indicating that optimal SVS improved passive body motion perception in a way that is consistent with classical SR theory. A probabilistic comparison to numeric simulations further validated these experimental results. On the second test session, 4 out of the 10 SR exhibitors showed repeated improvement with SVS compared to the no SVS condition. Data collection is ongoing for the last two test sessions in which SCC and OTO only perceptual motion recognition thresholds are being measured with SVS. The final results of these test sessions will give insight into whether vestibular perceptual SR can occur when only one type of vestibular sensor is sensing motion or if it is more evident when sensory integration between the SCC and OTO is occurring during the motion. The overall purpose of this research is to further quantify the effects of SVS on various sensorimotor tasks and to gain a more fundamental understanding of how SVS causes SR in the vestibular system. In the context of human space flight, results from this research will help in understanding how SVS may be practically implemented in the future as a component of a comprehensive countermeasure plan for G-transition adaptation.

Galvan-Garza, R. C.↗
DOE OSTI2020

Materials Data on SrIn4Pd by Materials Project

SrPdIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Sr is bonded in a 1-coordinate geometry to two equivalent Pd and thirteen In atoms. Both Sr–Pd bond lengths are 3.49 Å. There are a spread of Sr–In bond distances ranging from 3.36–3.93 Å. Pd is bonded in a 9-coordinate geometry to two equivalent Sr and seven In atoms. There are a spread of Pd–In bond distances ranging from 2.70–2.86 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 3-coordinate geometry to three equivalent Sr, three equivalent Pd, and one In atom. The In–In bond length is 3.23 Å. In the second In site, In is bonded in a distorted q6 geometry to four equivalent Sr and six In atoms. All In–In bond lengths are 3.24 Å. In the third In site, In is bonded in a 2-coordinate geometry to three equivalent Sr, one Pd, and four equivalent In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrIn4Ni by Materials Project

SrNiIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Sr is bonded in a 5-coordinate geometry to two equivalent Ni and thirteen In atoms. Both Sr–Ni bond lengths are 3.48 Å. There are a spread of Sr–In bond distances ranging from 3.39–3.80 Å. Ni is bonded in a 9-coordinate geometry to two equivalent Sr and seven In atoms. There are a spread of Ni–In bond distances ranging from 2.59–2.79 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 12-coordinate geometry to three equivalent Sr, three equivalent Ni, and one In atom. The In–In bond length is 3.29 Å. In the second In site, In is bonded in a 2-coordinate geometry to three equivalent Sr, one Ni, and four equivalent In atoms. All In–In bond lengths are 3.22 Å. In the third In site, In is bonded in a 10-coordinate geometry to four equivalent Sr and six In atoms.

36 MATERIALS SCIENCE↗