Materials Data on Eu3Si6N4O9 by Materials Project

Abstract

Eu3Si6N4O9 crystallizes in the trigonal P3 space group. The structure is three-dimensional. there are three inequivalent Eu2+ sites. In the first Eu2+ site, Eu2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.60 Å) and three longer (2.75 Å) Eu–O bond lengths. In the second Eu2+ site, Eu2+ is bonded in a 6-coordinate geometry to six O2- atoms. All Eu–O bond lengths are 2.62 Å. In the third Eu2+ site, Eu2+ is bonded to six O2- atoms to form distorted EuO6 octahedra that share corners with six SiN2O2 tetrahedra. There are three shorter (2.62 Å) and three longer (2.69 Å) Eu–O bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to two equivalent N3- and two O2- atoms to form SiN2O2 tetrahedra that share a cornercorner with one EuO6 octahedra and corners with five SiN2O2 tetrahedra. The corner-sharing octahedral tilt angles are 72°. There is one shorter (1.74 Å) and one longer (1.75 Å) Si–N bond length. There is one shorter (1.62 Å) and one longer (1.66 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to two N3- and two O2- atoms to form SiN2O2 tetrahedra that share a cornercorner with one EuO6 octahedra and corners with five SiN2O2 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There is one shorter (1.73 Å) and one longer (1.75 Å) Si–N bond length. There is one shorter (1.62 Å) and one longer (1.65 Å) Si–O bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a trigonal planar geometry to three equivalent Si4+ atoms. In the second N3- site, N3- is bonded in a trigonal planar geometry to three Si4+ atoms. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded to three Eu2+ and one Si4+ atom to form distorted corner-sharing OEu3Si tetrahedra. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three Eu2+ and one Si4+ atom.