DOE OSTI2020
CaEr15Si8Se11O28Cl crystallizes in the triclinic P1 space group. The structure is three-dimensional. Ca2+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Ca–Se bond distances ranging from 2.95–2.97 Å. There are a spread of Ca–O bond distances ranging from 2.36–2.51 Å. There are fifteen inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Er–Se bond distances ranging from 2.86–2.92 Å. There are a spread of Er–O bond distances ranging from 2.28–2.44 Å. In the second Er3+ site, Er3+ is bonded in a 9-coordinate geometry to two Se2-, six O2-, and one Cl1- atom. There are one shorter (2.89 Å) and one longer (2.91 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.30–2.60 Å. The Er–Cl bond length is 2.96 Å. In the third Er3+ site, Er3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Er–Se bond distances ranging from 2.83–2.92 Å. There are one shorter (2.29 Å) and two longer (2.42 Å) Er–O bond lengths. In the fourth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are one shorter (2.89 Å) and two longer (2.93 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.34–2.68 Å. In the fifth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are a spread of Er–Se bond distances ranging from 2.88–2.94 Å. There are a spread of Er–O bond distances ranging from 2.34–2.70 Å. In the sixth Er3+ site, Er3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are one shorter (2.85 Å) and two longer (2.91 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.29–2.44 Å. In the seventh Er3+ site, Er3+ is bonded in a 9-coordinate geometry to two Se2-, six O2-, and one Cl1- atom. There are one shorter (2.83 Å) and one longer (2.89 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.34–2.58 Å. The Er–Cl bond length is 2.95 Å. In the eighth Er3+ site, Er3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are two shorter (2.87 Å) and one longer (2.88 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.29–2.42 Å. In the ninth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are a spread of Er–Se bond distances ranging from 2.90–2.93 Å. There are a spread of Er–O bond distances ranging from 2.35–2.67 Å. In the tenth Er3+ site, Er3+ is bonded in a 3-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Er–Se bond distances ranging from 2.88–2.92 Å. There are a spread of Er–O bond distances ranging from 2.27–2.42 Å. In the eleventh Er3+ site, Er3+ is bonded in a 9-coordinate geometry to two Se2-, six O2-, and one Cl1- atom. There are one shorter (2.83 Å) and one longer (2.90 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.33–2.63 Å. The Er–Cl bond length is 2.95 Å. In the twelfth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to two Se2-, six O2-, and one Cl1- atom. There are one shorter (2.89 Å) and one longer (2.91 Å) Er–Se bond lengths. There are a spread of Er–O bond distances ranging from 2.30–2.61 Å. The Er–Cl bond length is 2.95 Å. In the thirteenth Er3+ site, Er3+ is bonded in a 3-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Er–Se bond distances ranging from 2.89–2.92 Å. There are a spread of Er–O bond distances ranging from 2.27–2.40 Å. In the fourteenth Er3+ site, Er3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are a spread of Er–Se bond distances ranging from 2.90–2.94 Å. There are a spread of Er–O bond distances ranging from 2.34–2.68 Å. In the fifteenth Er3+ site, Er3+ is bonded in a 3-coordinate geometry to three Se2- and three O2- atoms. There are a spread of Er–Se bond distances ranging from 2.87–2.91 Å. There are a spread of Er–O bond distances ranging from 2.27–2.43 Å. There are eight inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.64 Å) and one longer (1.66 Å) Si–O bond length. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are eleven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to one Ca2+, three Er3+, and two O2- atoms. There are one shorter (3.19 Å) and one longer (3.25 Å) Se–O bond lengths. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ and twelve O2- atoms. There are a spread of Se–O bond distances ranging from 3.13–3.24 Å. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. In the fifth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. In the sixth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. In the seventh Se2- site, Se2- is bonded in a 4-coordinate geometry to one Ca2+ and three Er3+ atoms. In the eighth Se2- site, Se2- is bonded in a 6-coordinate geometry to four Er3+ and two O2- atoms. There are one shorter (3.18 Å) and one longer (3.23 Å) Se–O bond lengths. In the ninth Se2- site, Se2- is bonded in a 4-coordinate geometry to one Ca2+ and three Er3+ atoms. In the tenth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. In the eleventh Se2- site, Se2- is bonded in a 4-coordinate geometry to four Er3+ atoms. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.19 Å. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.08 Å. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ and one Se2- atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.08 Å. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.19 Å. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.19 Å. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.09 Å. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ and one Se2- atom. In the twelfth O2- site, O2- is bonded to three Er3+, one Si4+, and one Se2- atom to form distorted edge-sharing OEr3SiSe tetrahedra. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, two Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.09 Å. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.08 Å. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the sixteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the seventeenth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.16 Å. In the eighteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ and one Se2- atom. In the nineteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Ca2+, two Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.10 Å. In the twentieth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the twenty-first O2- site, O2- is bonded in a 4-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the twenty-second O2- site, O2- is bonded to three Er3+, one Si4+, and one Se2- atom to form a mixture of distorted edge and corner-sharing OEr3SiSe tetrahedra. In the twenty-third O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the twenty-fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.07 Å. In the twenty-fifth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ and one Se2- atom. In the twenty-sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Se2- atom. In the twenty-seventh O2- site, O2- is bonded in a 1-coordinate geometry to three Er3+, one Si4+, and one Cl1- atom. The O–Cl bond length is 3.08 Å. In the twenty-eighth O2- site, O2- is bonded to three Er3+, one Si4+, and one Se2- atom to form a mixture of distorted edge and corner-sharing OEr3SiSe tetrahedra. Cl1- is bonded in a distorted rectangular see-saw-like geometry to four Er3+ and twelve O2- atoms.