DOE OSTI2020
Ca3Cu5Si9O26 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.38–2.72 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.37–2.88 Å. There are three inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There is two shorter (1.93 Å) and two longer (1.99 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 1.92–2.72 Å. In the third Cu2+ site, Cu2+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Cu–O bond distances ranging from 1.94–2.59 Å. There are five 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 1.61–1.66 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 1.62–1.68 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 1.62–1.69 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. All Si–O bond lengths are 1.64 Å. In the fifth 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 1.61–1.67 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Cu2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Cu2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cu2+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cu2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cu2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two equivalent Cu2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cu2+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Cu2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ca2+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, one Cu2+, and one Si4+ atom.