DOE OSTI2020
CdGa2O4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are twelve inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with three equivalent CdO6 octahedra and corners with nine GaO6 octahedra. The corner-sharing octahedra tilt angles range from 57–67°. There are three shorter (2.13 Å) and one longer (2.22 Å) Cd–O bond lengths. In the second Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with three equivalent CdO4 tetrahedra, corners with three equivalent GaO4 tetrahedra, and edges with six GaO6 octahedra. There are three shorter (2.24 Å) and three longer (2.32 Å) Cd–O bond lengths. In the third Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with three equivalent CdO6 octahedra and corners with nine GaO6 octahedra. The corner-sharing octahedra tilt angles range from 56–69°. There are three shorter (2.14 Å) and one longer (2.16 Å) Cd–O bond lengths. In the fourth Cd2+ site, Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with three equivalent CdO4 tetrahedra, corners with three equivalent GaO4 tetrahedra, and edges with six GaO6 octahedra. There are three shorter (2.26 Å) and three longer (2.31 Å) Cd–O bond lengths. In the fifth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 59–62°. There are one shorter (2.13 Å) and three longer (2.16 Å) Cd–O bond lengths. In the sixth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are three shorter (2.17 Å) and one longer (2.18 Å) Cd–O bond lengths. In the seventh Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 60–64°. There are three shorter (2.18 Å) and one longer (2.22 Å) Cd–O bond lengths. In the eighth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 61–62°. There are one shorter (2.15 Å) and three longer (2.17 Å) Cd–O bond lengths. In the ninth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 61–62°. There are one shorter (2.16 Å) and three longer (2.17 Å) Cd–O bond lengths. In the tenth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedral tilt angles are 61°. There are three shorter (2.17 Å) and one longer (2.18 Å) Cd–O bond lengths. In the eleventh Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 60–61°. There are three shorter (2.16 Å) and one longer (2.18 Å) Cd–O bond lengths. In the twelfth Cd2+ site, Cd2+ is bonded to four O2- atoms to form CdO4 tetrahedra that share corners with twelve GaO6 octahedra. The corner-sharing octahedra tilt angles range from 60–65°. There are three shorter (2.17 Å) and one longer (2.24 Å) Cd–O bond lengths. There are twelve inequivalent Ga3+ sites. In the first Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three equivalent CdO6 octahedra and corners with nine GaO6 octahedra. The corner-sharing octahedra tilt angles range from 53–63°. There is three shorter (1.93 Å) and one longer (1.98 Å) Ga–O bond length. In the second Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with three CdO4 tetrahedra, corners with three GaO4 tetrahedra, edges with two CdO6 octahedra, and edges with four equivalent GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.22 Å. In the third Ga3+ site, Ga3+ is bonded to four O2- atoms to form GaO4 tetrahedra that share corners with three equivalent CdO6 octahedra and corners with nine GaO6 octahedra. The corner-sharing octahedra tilt angles range from 52–63°. There is one shorter (1.93 Å) and three longer (1.97 Å) Ga–O bond length. In the fourth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share a cornercorner with one GaO4 tetrahedra, corners with five CdO4 tetrahedra, an edgeedge with one CdO6 octahedra, and edges with five GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 1.96–2.30 Å. In the fifth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are two shorter (2.03 Å) and four longer (2.05 Å) Ga–O bond lengths. In the sixth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are three shorter (2.02 Å) and three longer (2.04 Å) Ga–O bond lengths. In the seventh Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 2.03–2.05 Å. In the eighth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are three shorter (2.03 Å) and three longer (2.05 Å) Ga–O bond lengths. In the ninth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are a spread of Ga–O bond distances ranging from 2.03–2.05 Å. In the tenth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are three shorter (2.03 Å) and three longer (2.05 Å) Ga–O bond lengths. In the eleventh Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with two equivalent GaO4 tetrahedra, corners with four CdO4 tetrahedra, an edgeedge with one CdO6 octahedra, and edges with five GaO6 octahedra. There are four shorter (2.02 Å) and two longer (2.12 Å) Ga–O bond lengths. In the twelfth Ga3+ site, Ga3+ is bonded to six O2- atoms to form GaO6 octahedra that share corners with six CdO4 tetrahedra and edges with six GaO6 octahedra. There are three shorter (2.02 Å) and three longer (2.03 Å) Ga–O bond lengths. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Cd2+ and two equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCd2Ga2 trigonal pyramids. In the second O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 trigonal pyramids. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Cd2+ and three Ga3+ atoms. In the fourth O2- site, O2- is bonded to two Cd2+ and two equivalent Ga3+ atoms to form distorted OCd2Ga2 trigonal pyramids that share corners with four equivalent OCdGa3 tetrahedra, corners with three OCdGa3 trigonal pyramids, and edges with three OCd2Ga2 trigonal pyramids. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ga3+ atoms. In the sixth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form distorted OCdGa3 trigonal pyramids that share corners with nine OCdGa3 tetrahedra and edges with three equivalent OCd2Ga2 trigonal pyramids. In the seventh O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form OCdGa3 tetrahedra that share corners with six OCdGa3 tetrahedra, corners with six OCd2Ga2 trigonal pyramids, and edges with two equivalent OCdGa3 tetrahedra. In the eighth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ga3+ atoms. In the tenth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the eleventh O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the twelfth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the thirteenth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the fourteenth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the fifteenth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the sixteenth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the seventeenth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the eighteenth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the nineteenth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the twentieth O2- site, O2- is bonded to one Cd2+ and three Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the twenty-first O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form a mixture of distorted edge and corner-sharing OCdGa3 tetrahedra. In the twenty-second O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form distorted OCdGa3 trigonal pyramids that share corners with three equivalent OCdGa3 tetrahedra, corners with three equivalent OCd2Ga2 trigonal pyramids, and edges with three equivalent OCdGa3 tetrahedra. In the twenty-third O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Cd2+ and three Ga3+ atoms. In the twenty-fourth O2- site, O2- is bonded to one Cd2+ and three equivalent Ga3+ atoms to form corner-sharing OCdGa3 tetrahedra.