Materials Data on CaMg3Si3O10 by Materials Project
CaMg3Si3O10 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.33–2.68 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.67 Å. There are seven inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with four MgO6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are two shorter (2.03 Å) and four longer (2.15 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with four MgO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Mg–O bond distances ranging from 2.03–2.19 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with five SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.98–2.20 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with five SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.22 Å. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two MgO6 octahedra, corners with four SiO4 tetrahedra, and edges with six MgO6 octahedra. The corner-sharing octahedra tilt angles range from 13–15°. There are a spread of Mg–O bond distances ranging from 2.04–2.27 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.08–2.16 Å. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with four SiO4 tetrahedra and edges with five MgO6 octahedra. There are a spread of Mg–O bond distances ranging from 1.99–2.17 Å. There are six inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–63°. There are a spread of Si–O bond distances ranging from 1.59–1.69 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with five MgO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 45–61°. There are a spread of Si–O bond distances ranging from 1.62–1.71 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with five MgO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 41–61°. There are a spread of Si–O bond distances ranging from 1.62–1.72 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three MgO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 57–64°. There are a spread of Si–O bond distances ranging from 1.59–1.70 Å. In the fifth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six MgO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–58°. There are a spread of Si–O bond distances ranging from 1.63–1.74 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six MgO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–58°. There are a spread of Si–O bond distances ranging from 1.63–1.73 Å. There are twenty inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a see-saw-like geometry to four Mg2+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mg2+ and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Mg2+ and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a see-saw-like geometry to four Mg2+ atoms. In the fifteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the seventeenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Ca2+, two Mg2+, and one Si4+ atom. In the nineteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two Si4+ atoms. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Si4+ atoms.