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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Scalable Enrichment of 48 Ca at the Solid/liquid Interface by Chemical and Electrochemical Methods

This award targets to develop methods to enrich 48 Ca, which is a critical isotope for synthesizing superheavy elements and testing the standard model through neutrinoless double beta decay. The team first tested chemical exchange-based separation between solids and liquids, which is based on the free energy change due to the different vibrational frequencies caused by Ca isotopes in a material. However, the separation factor (alpha), which is defined as the ratio of 40 Ca/ 48 Ca ratios in the two phases, only reach ~1.01. The team then developed liquid centrifugation-based isotope separation, where a Ca salt aqueous solution is centrifuged at a speed of ~60 kRPM, and 48 Ca is enriched at the bottom of a centrifuge tube due to its larger mass. A high α of ~1.2-1.4 is achieved for 40 Ca/ 48 Ca at 40 °C. This method is further approved to be generic for any isotope that can be dissolved in a liquid solution or form liquid chemicals near room temperature. The experimental results also align well with modeling prediction. The team further develop a model to evaluate isotope separation in countercurrent liquid centrifugation. The team found that the countercurrent configuration can also enhance isotope separation in liquids, similar with gas centrifugation, which boost separation for isotopes which are difficult to be gasified near room temperature.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2026

Structure of high-lying excited states in 47 Ca with ℓ ≥ 3 populated in fast-beam 𝛾-ray-tagged one-neutron pickup reactions

Located just one neutron removed from doubly magic, stable 48 Ca, the adjacent isotope 47 Ca has been studied extensively with neutron-removing transfer reactions and interpreted within a shell-model picture. Neutron-adding transfer reactions onto the stable 46 Ca, however, have not been performed in nearly 60 years and never with the aid of high-resolution 𝛾-ray spectroscopy. Here, we report on the 12 C⁡( 46 , Ca 47 Ca+𝛾)⁢𝑋 one-neutron pickup reaction from 12 C onto 46 Ca at more than 50 MeV/nucleon, a regime of orbital angular momentum mismatch that selectively populates 47 Ca final states based on ℓ ≥ 3 neutron configurations. Newly observed excited states and 𝛾-ray transitions are discussed in comparison to 𝑓⁡𝑝 shell-model calculations in a variety of configuration spaces. Furthermore, it is shown that the nature of the observed spectrum of final states can be well interpreted, albeit with a significant fragmentation of the 𝜈⁢0⁢𝑓 5/2 strength observed in the measurement that is not borne out in the structure calculations.

39 ≤ A ≤ 58↗
DOE OSTI2020

Materials Data on Ca(Al2Cu)4 by Materials Project

Ca(CuAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca is bonded in a 12-coordinate geometry to eight equivalent Cu and twelve Al atoms. All Ca–Cu bond lengths are 3.39 Å. There are four shorter (3.09 Å) and eight longer (3.22 Å) Ca–Al bond lengths. Cu is bonded to two equivalent Ca, two equivalent Cu, and eight Al atoms to form a mixture of distorted edge, face, and corner-sharing CuCa2Al8Cu2 cuboctahedra. Both Cu–Cu bond lengths are 2.56 Å. There are four shorter (2.57 Å) and four longer (2.70 Å) Cu–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Ca, four equivalent Cu, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.82 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Ca, four equivalent Cu, and six Al atoms. Both Al–Al bond lengths are 2.76 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(MnAl2)4 by Materials Project

Ca(MnAl2)4 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca is bonded in a 4-coordinate geometry to eight equivalent Mn and twelve Al atoms. All Ca–Mn bond lengths are 3.36 Å. There are four shorter (2.92 Å) and eight longer (3.28 Å) Ca–Al bond lengths. Mn is bonded to two equivalent Ca, two equivalent Mn, and eight Al atoms to form distorted MnCa2Mn2Al8 cuboctahedra that share corners with eight equivalent AlCa2Mn4Al6 cuboctahedra, corners with ten equivalent MnCa2Mn2Al8 cuboctahedra, edges with four equivalent MnCa2Mn2Al8 cuboctahedra, edges with four equivalent AlCa2Mn4Al6 cuboctahedra, faces with six equivalent MnCa2Mn2Al8 cuboctahedra, and faces with eight equivalent AlCa2Mn4Al6 cuboctahedra. Both Mn–Mn bond lengths are 2.59 Å. There are four shorter (2.55 Å) and four longer (2.65 Å) Mn–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to two equivalent Ca, four equivalent Mn, and six Al atoms to form distorted AlCa2Mn4Al6 cuboctahedra that share corners with eight equivalent MnCa2Mn2Al8 cuboctahedra, corners with ten equivalent AlCa2Mn4Al6 cuboctahedra, edges with three equivalent AlCa2Mn4Al6 cuboctahedra, edges with four equivalent MnCa2Mn2Al8 cuboctahedra, faces with seven equivalent AlCa2Mn4Al6 cuboctahedra, and faces with eight equivalent MnCa2Mn2Al8 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.75–2.83 Å. In the second Al site, Al is bonded in a 10-coordinate geometry to one Ca, four equivalent Mn, and five Al atoms. The Al–Al bond length is 2.92 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(PIr)2 by Materials Project

Ca(IrP)2 crystallizes in the trigonal P3_221 space group. The structure is three-dimensional. Ca is bonded in a 11-coordinate geometry to five Ir and six equivalent P atoms. There are a spread of Ca–Ir bond distances ranging from 3.13–3.32 Å. There are a spread of Ca–P bond distances ranging from 3.02–3.17 Å. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 12-coordinate geometry to three equivalent Ca and four equivalent P atoms. There are two shorter (2.35 Å) and two longer (2.37 Å) Ir–P bond lengths. In the second Ir site, Ir is bonded in a 6-coordinate geometry to two equivalent Ca and four equivalent P atoms. There are two shorter (2.25 Å) and two longer (2.32 Å) Ir–P bond lengths. P is bonded to three equivalent Ca and four Ir atoms to form a mixture of distorted face, edge, and corner-sharing PCa3Ir4 pentagonal bipyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(BeGe)2 by Materials Project

CaBe2Ge2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ca is bonded in a 8-coordinate geometry to eight Be and eight Ge atoms. There are four shorter (3.08 Å) and four longer (3.16 Å) Ca–Be bond lengths. There are four shorter (3.06 Å) and four longer (3.22 Å) Ca–Ge bond lengths. There are two inequivalent Be sites. In the first Be site, Be is bonded in a 9-coordinate geometry to four equivalent Ca and five Ge atoms. There are one shorter (2.30 Å) and four longer (2.42 Å) Be–Ge bond lengths. In the second Be site, Be is bonded to four equivalent Ca and four equivalent Ge atoms to form distorted BeCa4Ge4 tetrahedra that share corners with twelve equivalent GeCa4Be4 tetrahedra, edges with two equivalent GeCa4Be4 tetrahedra, edges with four equivalent BeCa4Ge4 tetrahedra, and faces with four equivalent BeCa4Ge4 tetrahedra. All Be–Ge bond lengths are 2.40 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded to four equivalent Ca and four equivalent Be atoms to form distorted GeCa4Be4 tetrahedra that share corners with twelve equivalent BeCa4Ge4 tetrahedra, edges with two equivalent BeCa4Ge4 tetrahedra, edges with four equivalent GeCa4Be4 tetrahedra, and faces with four equivalent GeCa4Be4 tetrahedra. In the second Ge site, Ge is bonded in a 9-coordinate geometry to four equivalent Ca and five Be atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(WO2)2 by Materials Project

Ca(WO2)2 is Spinel-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 52–70°. There are a spread of Ca–O bond distances ranging from 2.27–2.33 Å. In the second Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 53–68°. There are a spread of Ca–O bond distances ranging from 2.23–2.34 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent CaO4 tetrahedra and edges with six WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.27–2.40 Å. In the fourth Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with twelve WO6 octahedra. The corner-sharing octahedra tilt angles range from 53–65°. There are a spread of Ca–O bond distances ranging from 2.25–2.39 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent WO4 trigonal pyramids, and edges with six WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.41 Å. In the sixth Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with twelve WO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Ca–O bond distances ranging from 2.26–2.33 Å. There are twelve inequivalent W3+ sites. In the first W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.30 Å. In the second W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.27 Å. In the third W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.29 Å. In the fourth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three CaO4 tetrahedra, a cornercorner with one WO4 trigonal pyramid, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.02–2.21 Å. In the fifth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.16–2.25 Å. In the sixth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six CaO4 tetrahedra and edges with six WO6 octahedra. There are a spread of W–O bond distances ranging from 2.16–2.24 Å. In the seventh W3+ site, W3+ is bonded in a distorted trigonal planar geometry to three O2- atoms. There are a spread of W–O bond distances ranging from 2.04–2.29 Å. In the eighth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.23 Å. In the ninth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with five CaO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.05–2.19 Å. In the tenth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.26 Å. In the eleventh W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with four CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of W–O bond distances ranging from 2.17–2.22 Å. In the twelfth W3+ site, W3+ is bonded to four O2- atoms to form distorted WO4 trigonal pyramids that share corners with three equivalent CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 42–75°. There are a spread of W–O bond distances ranging from 2.03–2.60 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the second O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the third O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share a cornercorner with one OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the fifth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the seventh O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with nine OCaW3 tetrahedra, corners with three equivalent OW4 trigonal pyramids, and edges with three OCa2W2 trigonal pyramids. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two W3+ atoms. In the ninth O2- site, O2- is bonded to four W3+ atoms to form distorted OW4 trigonal pyramids that share corners with three equivalent OCaW3 tetrahedra and corners with six OCa2W2 trigonal pyramids. In the tenth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the eleventh O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 trigonal pyramids that share corners with five OCaW3 tetrahedra, corners with four OW4 trigonal pyramids, an edgeedge with one OCaW3 tetrahedra, and edges with two OCa2W2 trigonal pyramids. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the thirteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the fourteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the fifteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the sixteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with three equivalent OCaW3 tetrahedra, corners with three OCa2W2 trigonal pyramids, and edges with three OCaW3 tetrahedra. In the seventeenth O2- site, O2- is bonded to four W3+ atoms to form distorted OW4 trigonal pyramids that share corners with three equivalent OCaW3 tetrahedra, corners with six OCa2W2 trigonal pyramids, and edges with three OCaW3 tetrahedra. In the eighteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the nineteenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form a mixture of distorted edge and corner-sharing OCaW3 tetrahedra. In the twentieth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with eight OCaW3 tetrahedra, corners with four OCa2W2 trigonal pyramids, edges with two OCaW3 tetrahedra, and an edgeedge with one OW4 trigonal pyramid. In the twenty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twenty-third O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted corner-sharing OCaW3 tetrahedra. In the twenty-fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(AgO2)2 by Materials Project

Ca(AgO2)2 is Spinel-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine AgO6 octahedra. The corner-sharing octahedra tilt angles range from 57–63°. There are a spread of Ca–O bond distances ranging from 2.24–2.34 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AgO4 tetrahedra, edges with two CaO6 octahedra, and edges with four AgO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.42 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four AgO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five AgO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.39 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AgO4 tetrahedra, edges with two CaO6 octahedra, and edges with four AgO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.38 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six AgO4 tetrahedra, edges with two CaO6 octahedra, and edges with four equivalent AgO6 octahedra. There are four shorter (2.30 Å) and two longer (2.36 Å) Ca–O bond lengths. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five AgO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five AgO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.31–2.36 Å. There are nine inequivalent Ag3+ sites. In the first Ag3+ site, Ag3+ is bonded to six O2- atoms to form AgO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four AgO4 tetrahedra, edges with three CaO6 octahedra, and edges with three AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.05–2.22 Å. In the second Ag3+ site, Ag3+ is bonded to four O2- atoms to form AgO4 tetrahedra that share corners with six CaO6 octahedra and corners with six AgO6 octahedra. The corner-sharing octahedra tilt angles range from 55–63°. There are a spread of Ag–O bond distances ranging from 2.19–2.28 Å. In the third Ag3+ site, Ag3+ is bonded to six O2- atoms to form AgO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent AgO4 tetrahedra, edges with two CaO6 octahedra, and edges with four AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.10–2.27 Å. In the fourth Ag3+ site, Ag3+ is bonded to six O2- atoms to form AgO6 octahedra that share corners with six AgO4 tetrahedra, edges with two equivalent AgO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.06–2.19 Å. In the fifth Ag3+ site, Ag3+ is bonded to four O2- atoms to form AgO4 tetrahedra that share corners with six CaO6 octahedra and corners with six AgO6 octahedra. The corner-sharing octahedra tilt angles range from 53–64°. There are one shorter (2.17 Å) and three longer (2.20 Å) Ag–O bond lengths. In the sixth Ag3+ site, Ag3+ is bonded to six O2- atoms to form AgO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five AgO4 tetrahedra, edges with three CaO6 octahedra, and edges with three AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.05–2.28 Å. In the seventh Ag3+ site, Ag3+ is bonded to four O2- atoms to form AgO4 tetrahedra that share corners with six CaO6 octahedra and corners with six AgO6 octahedra. The corner-sharing octahedra tilt angles range from 52–65°. There are a spread of Ag–O bond distances ranging from 2.19–2.21 Å. In the eighth Ag3+ site, Ag3+ is bonded to four O2- atoms to form AgO4 tetrahedra that share corners with six CaO6 octahedra and corners with six AgO6 octahedra. The corner-sharing octahedra tilt angles range from 55–64°. There are a spread of Ag–O bond distances ranging from 2.18–2.33 Å. In the ninth Ag3+ site, Ag3+ is bonded to four O2- atoms to form AgO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine AgO6 octahedra. The corner-sharing octahedra tilt angles range from 55–68°. There are a spread of Ag–O bond distances ranging from 2.15–2.27 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two Ag3+ atoms to form distorted OCa2Ag2 tetrahedra that share corners with two OCa2Ag2 tetrahedra, corners with five OCaAg3 trigonal pyramids, an edgeedge with one OCa2Ag2 tetrahedra, and an edgeedge with one OCaAg3 trigonal pyramid. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the third O2- site, O2- is bonded to one Ca2+ and three Ag3+ atoms to form distorted OCaAg3 trigonal pyramids that share corners with three OCa2Ag2 tetrahedra, corners with four OCaAg3 trigonal pyramids, and edges with two equivalent OCa2Ag2 tetrahedra. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two Ag3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ag3+ atoms. In the eighth O2- site, O2- is bonded to one Ca2+ and three Ag3+ atoms to form distorted OCaAg3 trigonal pyramids that share corners with four equivalent OCa2Ag2 tetrahedra and corners with four OCaAg3 trigonal pyramids. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ag3+ atoms. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two Ag3+ atoms. In the thirteenth O2- site, O2- is bonded to two Ca2+ and two equivalent Ag3+ atoms to form distorted OCa2Ag2 tetrahedra that share corners with two equivalent OCa2Ag2 tetrahedra and corners with eight OCaAg3 trigonal pyramids. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ag3+ atoms. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ag3+ atoms. In the seventeenth O2- site, O2- is bonded to one Ca2+ and three Ag3+ atoms to form distorted OCaAg3 trigonal pyramids that share corners with four OCa2Ag2 tetrahedra, corners with three OCaAg3 trigonal pyramids, and edges with two OCaAg3 trigonal pyramids. In the eighteenth O2- site, O2- is bonded to one Ca2+ and three Ag3+ atoms to form distorted OCaAg3 trigonal pyramids that share corners with three equivalent OCa2Ag2 tetrahedra and edges with two equivalent OCaAg3 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(SnO2)2 by Materials Project

Ca(SnO2)2 is Ilmenite-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine SnO6 octahedra. The corner-sharing octahedra tilt angles range from 52–69°. There are a spread of Ca–O bond distances ranging from 2.23–2.50 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are two shorter (2.39 Å) and four longer (2.44 Å) Ca–O bond lengths. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four SnO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.35–2.42 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.35–2.44 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with six SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four equivalent SnO6 octahedra. There are two shorter (2.34 Å) and four longer (2.42 Å) Ca–O bond lengths. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five SnO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five SnO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.33–2.41 Å. There are nine inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four SnO4 tetrahedra, edges with three CaO6 octahedra, and edges with three SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.09–2.19 Å. In the second Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–74°. There are a spread of Sn–O bond distances ranging from 2.13–2.71 Å. In the third Sn3+ site, Sn3+ is bonded to six O2- atoms to form distorted SnO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent SnO4 tetrahedra, edges with two CaO6 octahedra, and edges with four SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.29–2.72 Å. In the fourth Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six SnO4 tetrahedra, edges with two equivalent SnO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.10–2.14 Å. In the fifth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 52–74°. There are a spread of Sn–O bond distances ranging from 2.13–2.72 Å. In the sixth Sn3+ site, Sn3+ is bonded to six O2- atoms to form SnO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five SnO4 tetrahedra, edges with three CaO6 octahedra, and edges with three SnO6 octahedra. There are a spread of Sn–O bond distances ranging from 2.10–2.18 Å. In the seventh Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–73°. There are a spread of Sn–O bond distances ranging from 2.13–2.71 Å. In the eighth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with six CaO6 octahedra and corners with six SnO6 octahedra. The corner-sharing octahedra tilt angles range from 51–74°. There are a spread of Sn–O bond distances ranging from 2.14–2.71 Å. In the ninth Sn3+ site, Sn3+ is bonded to four O2- atoms to form distorted SnO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine SnO6 octahedra. The corner-sharing octahedra tilt angles range from 48–75°. There are a spread of Sn–O bond distances ranging from 2.10–2.77 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with five OCa2Sn2 tetrahedra, a cornercorner with one OSn4 trigonal pyramid, and an edgeedge with one OCa2Sn2 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Sn3+ atoms. In the fourth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCa2Sn2 tetrahedra. In the fifth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the seventh O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with eight OCa2Sn2 tetrahedra and edges with two OCaSn3 tetrahedra. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the ninth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the tenth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with five OCa2Sn2 tetrahedra, a cornercorner with one OSn4 trigonal pyramid, and edges with two OCa2Sn2 tetrahedra. In the eleventh O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form a mixture of distorted corner and edge-sharing OCaSn3 tetrahedra. In the twelfth O2- site, O2- is bonded to two Ca2+ and two Sn3+ atoms to form distorted OCa2Sn2 tetrahedra that share corners with nine OCa2Sn2 tetrahedra and edges with two OCaSn3 tetrahedra. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two equivalent Sn3+ atoms. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the fifteenth O2- site, O2- is bonded to one Ca2+ and three Sn3+ atoms to form distorted OCaSn3 tetrahedra that share corners with five OCa2Sn2 tetrahedra, corners with two equivalent OSn4 trigonal pyramids, and edges with two equivalent OCa2Sn2 tetrahedra. In the sixteenth O2- site, O2- is bonded to four Sn3+ atoms to form distorted corner-sharing OSn4 trigonal pyramids. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Sn3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(NiO2)2 by Materials Project

Ca(NiO2)2 is Spinel-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 55–75°. There are a spread of Ca–O bond distances ranging from 2.16–2.31 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six NiO4 tetrahedra, edges with two CaO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.26–2.33 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four NiO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five NiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.22–2.28 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six NiO4 tetrahedra, edges with two CaO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.24–2.31 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six NiO4 tetrahedra, edges with two CaO6 octahedra, and edges with four equivalent NiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.24–2.30 Å. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five NiO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five NiO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.25–2.27 Å. There are nine inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four NiO4 tetrahedra, edges with three CaO6 octahedra, and edges with three NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.86–2.17 Å. In the second Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six CaO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 49–61°. There are a spread of Ni–O bond distances ranging from 1.87–1.96 Å. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent NiO4 tetrahedra, edges with two CaO6 octahedra, and edges with four NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.86–1.94 Å. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six NiO4 tetrahedra, edges with two equivalent NiO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.91–2.16 Å. In the fifth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six CaO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Ni–O bond distances ranging from 1.85–1.92 Å. In the sixth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five NiO4 tetrahedra, edges with three CaO6 octahedra, and edges with three NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 1.92–2.32 Å. In the seventh Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six CaO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 50–67°. There are a spread of Ni–O bond distances ranging from 1.91–2.07 Å. In the eighth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with six CaO6 octahedra and corners with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 51–69°. There are a spread of Ni–O bond distances ranging from 1.91–2.09 Å. In the ninth Ni3+ site, Ni3+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–66°. There are a spread of Ni–O bond distances ranging from 1.95–2.19 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ca2+ and two Ni3+ atoms to form distorted OCa2Ni2 tetrahedra that share corners with two OCa2Ni2 tetrahedra, corners with three OCaNi3 trigonal pyramids, an edgeedge with one OCa2Ni2 tetrahedra, and an edgeedge with one OCaNi3 trigonal pyramid. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the third O2- site, O2- is bonded to one Ca2+ and three Ni3+ atoms to form distorted OCaNi3 trigonal pyramids that share corners with three OCa2Ni2 tetrahedra, corners with two equivalent OCaNi3 trigonal pyramids, and edges with two equivalent OCa2Ni2 tetrahedra. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ni3+ atoms. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ni3+ atoms. In the eighth O2- site, O2- is bonded to one Ca2+ and three Ni3+ atoms to form distorted OCaNi3 trigonal pyramids that share corners with four equivalent OCa2Ni2 tetrahedra and corners with two equivalent OCaNi3 trigonal pyramids. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ni3+ atoms. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ni3+ atoms. In the thirteenth O2- site, O2- is bonded to two Ca2+ and two equivalent Ni3+ atoms to form distorted OCa2Ni2 tetrahedra that share corners with two equivalent OCa2Ni2 tetrahedra and a cornercorner with one OCaNi3 trigonal pyramid. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni3+ atoms. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms. In the eighteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Ni3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(WO2)2 by Materials Project

Ca(WO2)2 is beta indium sulfide-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 54–67°. There are three shorter (2.28 Å) and one longer (2.35 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent WO4 trigonal pyramids, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.27–2.42 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one WO4 tetrahedra, corners with two equivalent CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.31–2.42 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent WO4 trigonal pyramids, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.41 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two WO4 trigonal pyramids, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.22–2.49 Å. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with two equivalent WO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, an edgeedge with one CaO6 octahedra, and edges with five WO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.27–2.41 Å. There are twelve inequivalent W3+ sites. In the first W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one WO4 tetrahedra, corners with two equivalent CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, edges with three CaO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.14–2.21 Å. In the second W3+ site, W3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of W–O bond distances ranging from 1.97–2.07 Å. In the third W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent WO4 tetrahedra, edges with two CaO6 octahedra, and edges with four WO6 octahedra. There are a spread of W–O bond distances ranging from 2.06–2.27 Å. In the fourth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one WO4 tetrahedra, corners with two equivalent CaO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, edges with three CaO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.18–2.24 Å. In the fifth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with two WO4 trigonal pyramids, edges with two equivalent WO6 octahedra, and edges with four CaO6 octahedra. There are a spread of W–O bond distances ranging from 2.15–2.24 Å. In the sixth W3+ site, W3+ is bonded to four O2- atoms to form WO4 trigonal pyramids that share corners with six CaO6 octahedra and corners with six WO6 octahedra. The corner-sharing octahedra tilt angles range from 39–70°. There are a spread of W–O bond distances ranging from 1.97–2.36 Å. In the seventh W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with two WO4 trigonal pyramids, edges with two equivalent WO6 octahedra, and edges with four CaO6 octahedra. There are a spread of W–O bond distances ranging from 2.00–2.23 Å. In the eighth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with two equivalent WO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, edges with three CaO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.14–2.22 Å. In the ninth W3+ site, W3+ is bonded to four O2- atoms to form WO4 trigonal pyramids that share corners with six CaO6 octahedra and corners with six WO6 octahedra. The corner-sharing octahedra tilt angles range from 43–79°. There are a spread of W–O bond distances ranging from 2.07–2.35 Å. In the tenth W3+ site, W3+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with two equivalent WO4 tetrahedra, corners with two equivalent WO4 trigonal pyramids, edges with three CaO6 octahedra, and edges with three WO6 octahedra. There are a spread of W–O bond distances ranging from 2.15–2.26 Å. In the eleventh W3+ site, W3+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of W–O bond distances ranging from 1.97–2.04 Å. In the twelfth W3+ site, W3+ is bonded to four O2- atoms to form distorted WO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine WO6 octahedra. The corner-sharing octahedra tilt angles range from 51–75°. There are a spread of W–O bond distances ranging from 2.04–2.53 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the third O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 tetrahedra that share corners with two OCa2W2 tetrahedra, corners with four OCaW3 trigonal pyramids, and an edgeedge with one OCaW3 tetrahedra. In the fourth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 tetrahedra that share corners with two OCa2W2 tetrahedra, corners with four OCaW3 trigonal pyramids, and an edgeedge with one OCa2W2 tetrahedra. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the ninth O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Ca2+ and one W3+ atom. In the tenth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form OCaW3 trigonal pyramids that share corners with four OCa2W2 tetrahedra and corners with two OCaW3 trigonal pyramids. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ca2+ and one W3+ atom. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the seventeenth O2- site, O2- is bonded to two Ca2+ and two W3+ atoms to form distorted OCa2W2 tetrahedra that share corners with two OCa2W2 tetrahedra and corners with four OCaW3 trigonal pyramids. In the eighteenth O2- site, O2- is bonded in a trigonal pyramidal geometry to one Ca2+ and three W3+ atoms. In the nineteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twentieth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two W3+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four W3+ atoms. In the twenty-second O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 trigonal pyramids that share corners with four OCa2W2 tetrahedra, corners with two OCaW3 trigonal pyramids, and an edgeedge with one OCaW3 trigonal pyramid. In the twenty-third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three W3+ atoms. In the twenty-fourth O2- site, O2- is bonded to one Ca2+ and three W3+ atoms to form distorted OCaW3 trigonal pyramids that share corners with four OCa2W2 tetrahedra, corners with two OCaW3 trigonal pyramids, and an edgeedge with one OCaW3 trigonal pyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(MoO2)2 by Materials Project

Ca(MoO2)2 is Spinel-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form CaO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine MoO6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are a spread of Ca–O bond distances ranging from 2.19–2.27 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six MoO4 tetrahedra, edges with two CaO6 octahedra, and edges with four MoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.39 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four MoO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five MoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.26–2.42 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six MoO4 tetrahedra, edges with two CaO6 octahedra, and edges with four MoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.30–2.40 Å. In the fifth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six MoO4 tetrahedra, edges with two CaO6 octahedra, and edges with four MoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.32–2.39 Å. In the sixth Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five MoO4 tetrahedra, an edgeedge with one CaO6 octahedra, and edges with five MoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.25–2.48 Å. There are twelve inequivalent Mo3+ sites. In the first Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four MoO4 tetrahedra, edges with three CaO6 octahedra, and edges with three MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.13–2.28 Å. In the second Mo3+ site, Mo3+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with six CaO6 octahedra and corners with six MoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–66°. There are a spread of Mo–O bond distances ranging from 1.99–2.21 Å. In the third Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with three equivalent CaO4 tetrahedra, corners with three equivalent MoO4 tetrahedra, edges with two CaO6 octahedra, and edges with four MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.08–2.28 Å. In the fourth Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with two equivalent CaO4 tetrahedra, corners with four MoO4 tetrahedra, edges with three CaO6 octahedra, and edges with three MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.13–2.28 Å. In the fifth Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six MoO4 tetrahedra, edges with two equivalent MoO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.16–2.26 Å. In the sixth Mo3+ site, Mo3+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with six CaO6 octahedra and corners with six MoO6 octahedra. The corner-sharing octahedra tilt angles range from 44–77°. There are a spread of Mo–O bond distances ranging from 2.09–2.25 Å. In the seventh Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six MoO4 tetrahedra, edges with two equivalent MoO6 octahedra, and edges with four CaO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.15–2.24 Å. In the eighth Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five MoO4 tetrahedra, edges with three CaO6 octahedra, and edges with three MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.10–2.36 Å. In the ninth Mo3+ site, Mo3+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with six CaO6 octahedra and corners with six MoO6 octahedra. The corner-sharing octahedra tilt angles range from 44–71°. There are a spread of Mo–O bond distances ranging from 2.08–2.20 Å. In the tenth Mo3+ site, Mo3+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one CaO4 tetrahedra, corners with five MoO4 tetrahedra, edges with three CaO6 octahedra, and edges with three MoO6 octahedra. There are a spread of Mo–O bond distances ranging from 2.13–2.32 Å. In the eleventh Mo3+ site, Mo3+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with six CaO6 octahedra and corners with six MoO6 octahedra. The corner-sharing octahedra tilt angles range from 46–76°. There are a spread of Mo–O bond distances ranging from 2.07–2.26 Å. In the twelfth Mo3+ site, Mo3+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with three CaO6 octahedra and corners with nine MoO6 octahedra. The corner-sharing octahedra tilt angles range from 48–62°. There are a spread of Mo–O bond distances ranging from 1.98–2.04 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the fourth O2- site, O2- is bonded to one Ca2+ and three Mo3+ atoms to form distorted corner-sharing OCaMo3 trigonal pyramids. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the sixth O2- site, O2- is bonded to one Ca2+ and three Mo3+ atoms to form corner-sharing OCaMo3 trigonal pyramids. In the seventh O2- site, O2- is bonded in a trigonal pyramidal geometry to one Ca2+ and three Mo3+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the tenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the eleventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the twelfth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the thirteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the fourteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the seventeenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the eighteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the nineteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the twentieth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Mo3+ atoms. In the twenty-first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Mo3+ atoms. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms. In the twenty-third O2- site, O2- is bonded in a trigonal pyramidal geometry to one Ca2+ and three Mo3+ atoms. In the twenty-fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+ and three Mo3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(SiO2)8 by Materials Project

Ca(SiO2)8 is Low Tridymite-derived structured and crystallizes in the monoclinic Pc space group. The structure is three-dimensional. Ca is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Ca–O bond distances ranging from 2.56–2.70 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the second Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the third Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the fourth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the fifth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the sixth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.65 Å. In the seventh Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the eighth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. There are sixteen inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one Ca and two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and two Si atoms. In the eighth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the ninth O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and two Si atoms. In the twelfth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the thirteenth O site, O is bonded in a linear geometry to two Si atoms. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(SO5)2 by Materials Project

Ca(SO5)2 crystallizes in the hexagonal P6_2 space group. The structure is three-dimensional. Ca is bonded in a distorted hexagonal bipyramidal geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.96 Å. S is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of S–O bond distances ranging from 1.44–1.49 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and one O atom. The O–O bond length is 1.22 Å. In the second O site, O is bonded in a single-bond geometry to one S atom. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and one O atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Ca and one S atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Ca and one S atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ca(SO5)2 by Materials Project

Ca(SO5)2 crystallizes in the hexagonal P6_4 space group. The structure is three-dimensional. Ca is bonded in a distorted hexagonal bipyramidal geometry to eight O atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.96 Å. S is bonded in a trigonal non-coplanar geometry to three O atoms. There are a spread of S–O bond distances ranging from 1.44–1.49 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and one O atom. The O–O bond length is 1.22 Å. In the second O site, O is bonded in a bent 150 degrees geometry to one Ca and one S atom. In the third O site, O is bonded in a bent 150 degrees geometry to one Ca and one S atom. In the fourth O site, O is bonded in a single-bond geometry to one S atom. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one Ca and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Trap‐Engineering the Persistent Luminescence of Ca 3 Ga 4 O 9 :Tb 3+ via Al 3+ Substitution for Optical Data Storage

Abstract Optically stimulated luminescence (OSL) materials hold great potential for optical data storage (ODS) and anticounterfeiting applications. Nevertheless, the scarcity of suitable luminescent materials with deep‐level traps remains a significant obstacle. Herein, a host substation strategy have been employed to tune the persistent luminescence (PersL) and OSL properties of Ca 3 Ga 4 O 9 :Tb 3+ by Al 3+ substitution through trap engineering and demonstrated their potential. Specifically, the photoluminescence of the Ca 2.985 (Ga 1‐y% Al y% ) 4 O 9 :0.5%Tb 3+ of Tb 3+ is first investigated due to its different occupancies of Ca 2+ . The influence of host substitution on the crystal structure, trap depth, trap density, PersL, and OSL properties have further investigated. A series of strong PersL and OSL peaks from the Ca 2.985 (Ga 1‐y% Al y% ) 4 O 9 :0.5%Tb 3+ with bluish‐green emissions have been observed. The Ca 2.985 (Ga 1‐y% Al y% ) 4 O 9 :0.5%Tb 3+ have shown controllable photon release upon thermal and optical stimuli, enhancing their performance for ODS. Thermally stimulated luminescence suggests that vacancy and defect concentrations inside the Ca 3‐x% (Ga 1‐y% Al y% ) 4 O 9 :x%Tb 3+ can be manipulated by Tb 3+ doping and Al 3+ substitution, which ultimately leads to the formation of deep traps and a broad distribution of traps with increased deep trap concentration. The work demonstrates that trap engineering through Al 3 ⁺ substitution is an effective method for tuning PersL and OSL properties of Ca 2.985 (Ga 1‐y% Al y% ) 4 O 9 :0.5%Tb 3+ for ODS.

Abeywickrama, Thulitha M. [Department of Chemistry↗
DOE OSTI2022

Structural Complexity and Tuned Thermoelectric Properties of a Polymorph of the Zintl Phase Ca 2 CdSb 2 with a Non-centrosymmetric Monoclinic Structure

The Zintl phase Ca 2 CdSb 2 was found to be dimorphic. Besides the orthorhombic Ca 2 CdSb 2 (-o), here we report on the synthesis, the structural characterization, and the thermoelectric transport properties of its monoclinic form, Ca 2 CdSb 2 (-m), and its Lu-doped variant Ca 2–x Lu x CdSb 2 (x ≈ 0.02). The monoclinic structure exhibits complex structural characteristics and constitutes a new structure type with the non-centrosymmetric space group Cm (Z = 30). The electrical resistivity ρ(T) measured on single crystals of both phases portrays a transition from a semiconductor to a degenerate p-type semiconductor upon doping with Lu and with an attendant change in the Hall carrier concentration nH from 7.15 × 10 18 to 2.30 × 10 19 cm –3 at 300 K. The Seebeck coefficient S(T) of both phases are comparable and indicate a hole-dominated carrier transport mechanism with magnitudes of 133 and 116 μV/K at 600 K for Ca 2 CdSb 2 (-m) and Ca 2–x Lu x CdSb 2 , respectively. The convoluted atomic bonding with an attendant large unit cell volume of ~4365 Å 3 drives a putative low thermal conductivity in these materials resulting in a power factor PF of 1.63 μW/cm K 2 and an estimated thermoelectric figure of merit zT of ~0.5 for Ca 2–x Lu x CdSb 2 at 600 K. Furthermore, differential scanning calorimetry results reveal the stability of these phases up to about 960 K, making them candidates for moderate temperature thermoelectric materials.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Synthesis and structural characterization of Ca 12 Ga 14 O 33

Ca 12 Ga 14 O 33 was successfully synthesized using a wet chemistry technique to promote the homogenous mixing of the Ca and Ga cations. Rietveld refinements on X-ray and neutron powder diffraction data confirm that the compound is isostructural to Ca 12 Al 14 O 33 , however, with a significantly larger lattice parameter allowing for the cages that result from the framework arrangement to expand. In naturally occurring Ca 12 Al 14 O 33 , the mineral mayenite, these cages are occupied by O 2- anions, however, experimental studies exchanging the O 2- anions with other anions has led to a host of applications, depending on the caged anion. The functional nature of the structure, where framework distortions coupled with cage occupants, are correlated to electronic band structure and modifications to the framework could lead to interesting physical properties. The phase evolution was tracked using thermogravimetric analysis and high temperature X-ray diffraction and showed a lower formation temperature for the Ca 12 Ga 14 O 33 analogue compared to Ca 12 Al 14 O 33 synthesized using the same wet chemistry technique. Analyzing both X-ray and neutron powder diffraction using the Rietveld method with two different starting models results in one structural model, with one Ca position and the caged O on a 24d special position, being preferred.

36 MATERIALS SCIENCE↗