Materials Data on Er2Si2O7 by Materials Project

Abstract

Er2Si2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Er3+ is bonded to six O2- atoms to form distorted ErO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with three equivalent ErO6 octahedra. There are a spread of Er–O bond distances ranging from 2.23–2.32 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six equivalent ErO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–61°. There is three shorter (1.64 Å) and one longer (1.65 Å) Si–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Er3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Er3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Er3+ and one Si4+ atom.