Materials Data on K2MgSi5O12 by Materials Project
K2MgSi5O12 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.85–3.36 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.08 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.81–3.24 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.70–3.38 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.96–1.98 Å. In the second Mg2+ site, Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four SiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.94–1.98 Å. There are ten inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.68 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 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 1.62–1.64 Å. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.58–1.67 Å. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one MgO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Mg2+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Mg2+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Mg2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Mg2+, and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Mg2+, and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Mg2+, and one Si4+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Si4+ atoms. In the twentieth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two Si4+ atoms. In the twenty-first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Mg2+, and one Si4+ atom. In the twenty-second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two Si4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one K1+, one Mg2+, and one Si4+ atom.