DOE OSTI2020
Ba4Er3F17 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.64–3.19 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Ba–F bond distances ranging from 2.62–2.93 Å. In the third Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.64–3.17 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.65–3.19 Å. In the fifth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.65–3.16 Å. In the sixth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.65–3.17 Å. In the seventh Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Ba–F bond distances ranging from 2.62–2.93 Å. In the eighth Ba2+ site, Ba2+ is bonded in a 11-coordinate geometry to eleven F1- atoms. There are a spread of Ba–F bond distances ranging from 2.64–3.15 Å. There are six inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.24–2.37 Å. In the second Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.25–2.39 Å. In the third Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.24–2.37 Å. In the fourth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Er–F bond distances ranging from 2.24–2.51 Å. In the fifth Er3+ site, Er3+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Er–F bond distances ranging from 2.25–2.43 Å. In the sixth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Er–F bond distances ranging from 2.24–2.64 Å. There are thirty-four inequivalent F1- sites. In the first F1- site, F1- is bonded to six Ba2+ atoms to form a mixture of distorted face and corner-sharing FBa6 octahedra. In the second F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with eight FBa3Er tetrahedra, and edges with five FBa3Er tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. In the third F1- site, F1- is bonded to four Ba2+ atoms to form FBa4 tetrahedra that share corners with eleven FBa2Er2 tetrahedra, edges with four FBa3Er tetrahedra, and a faceface with one FBa6 octahedra. In the fourth F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with three FBa2Er2 tetrahedra. The corner-sharing octahedral tilt angles are 58°. In the fifth F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with four FBa3Er tetrahedra. The corner-sharing octahedra tilt angles range from 52–65°. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to three Ba2+ and one Er3+ atom. In the seventh F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with eight FBa3Er tetrahedra, and edges with five FBa3Er tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. In the eighth F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with three FBa2Er2 tetrahedra. The corner-sharing octahedral tilt angles are 58°. In the ninth F1- site, F1- is bonded in a 4-coordinate geometry to three Ba2+ and one Er3+ atom. In the tenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the eleventh F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the twelfth F1- site, F1- is bonded in a 2-coordinate geometry to two Ba2+ and two Er3+ atoms. In the thirteenth F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with four FBa3Er tetrahedra. The corner-sharing octahedral tilt angles are 57°. In the fourteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the fifteenth F1- site, F1- is bonded in a 4-coordinate geometry to three Ba2+ and one Er3+ atom. In the sixteenth F1- site, F1- is bonded in a 2-coordinate geometry to two Ba2+ and two Er3+ atoms. In the seventeenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the eighteenth F1- site, F1- is bonded in a distorted water-like geometry to two Er3+ atoms. In the nineteenth F1- site, F1- is bonded in a 2-coordinate geometry to two Ba2+ and two Er3+ atoms. In the twentieth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the twenty-first F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with nine FBa2Er2 tetrahedra, edges with five FBa3Er tetrahedra, and a faceface with one FBa6 octahedra. In the twenty-second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Ba2+ and two Er3+ atoms. In the twenty-third F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with eight FBa3Er tetrahedra, and edges with three FBa3Er tetrahedra. The corner-sharing octahedral tilt angles are 58°. In the twenty-fourth F1- site, F1- is bonded in a 2-coordinate geometry to two Ba2+ and two Er3+ atoms. In the twenty-fifth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Ba2+ and two Er3+ atoms. In the twenty-sixth F1- site, F1- is bonded in a 2-coordinate geometry to two Ba2+ and two Er3+ atoms. In the twenty-seventh F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with ten FBa3Er tetrahedra, edges with four FBa3Er tetrahedra, and a faceface with one FBa6 octahedra. In the twenty-eighth F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with eight FBa3Er tetrahedra, and edges with four FBa3Er tetrahedra. The corner-sharing octahedral tilt angles are 58°. In the twenty-ninth F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with four FBa2Er2 tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. In the thirtieth F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with ten FBa3Er tetrahedra, edges with four FBa3Er tetrahedra, and a faceface with one FBa6 octahedra. In the thirty-first F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with eight FBa4 tetrahedra, and edges with five FBa3Er tetrahedra. The corner-sharing octahedra tilt angles range from 52–64°. In the thirty-second F1- site, F1- is bonded to two Ba2+ and two Er3+ atoms to form distorted FBa2Er2 tetrahedra that share a cornercorner with one FBa6 octahedra, corners with eight FBa3Er tetrahedra, and edges with four FBa3Er tetrahedra. The corner-sharing octahedral tilt angles are 57°. In the thirty-third F1- site, F1- is bonded to four Ba2+ atoms to form FBa4 tetrahedra that share corners with ten FBa3Er tetrahedra, edges with five FBa3Er tetrahedra, and a faceface with one FBa6 octahedra. In the thirty-fourth F1- site, F1- is bonded to three Ba2+ and one Er3+ atom to form distorted FBa3Er tetrahedra that share corners with two equivalent FBa6 octahedra, corners with nine FBa3Er tetrahedra, and edges with four FBa2Er2 tetrahedra. The corner-sharing octahedra tilt angles range from 52–65°.