Materials Data on K2Cu(Si2O5)2 by Materials Project
K2Cu(Si2O5)2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.06 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.72–3.09 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.83–3.29 Å. In the fourth 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 2.80–3.05 Å. Cu2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.95–1.97 Å. There are four 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 1.60–1.66 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 1.59–1.67 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 1.59–1.66 Å. In the fourth 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 1.60–1.66 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two K1+ and two Si4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two K1+, one Cu2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Si4+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two K1+, one Cu2+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Cu2+, and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent K1+, one Cu2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+ and two Si4+ atoms. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two equivalent Si4+ atoms.