Materials Data on KErP2O7 by Materials Project

Abstract

KErP2O7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.95–3.56 Å. Er3+ is bonded to six O2- atoms to form ErO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Er–O bond distances ranging from 2.18–2.27 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent ErO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 16–50°. There is three shorter (1.53 Å) and one longer (1.63 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent ErO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 14–47°. There are a spread of P–O bond distances ranging from 1.51–1.63 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one K1+, one Er3+, and one P5+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+ and two P5+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Er3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Er3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, one Er3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Er3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted linear geometry to one K1+, one Er3+, and one P5+ atom.