Materials Data on Er2SiO5 by Materials Project

Er2SiO5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Er–O bond distances ranging from 2.21–2.60 Å. In the second Er3+ site, Er3+ is bonded to seven O2- atoms to form distorted ErO7 pentagonal bipyramids that share corners with four equivalent SiO4 tetrahedra, edges with three equivalent ErO7 pentagonal bipyramids, and an edgeedge with one SiO4 tetrahedra. There are a spread of Er–O bond distances ranging from 2.24–2.44 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent ErO7 pentagonal bipyramids and an edgeedge with one ErO7 pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.62–1.68 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Er3+ atoms to form a mixture of edge and corner-sharing OEr4 tetrahedra. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Er3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Er3+ and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Er3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Er3+ and one Si4+ atom.