DOI: 10.17188/1662711
title: Materials Data on MgBi4(PO6)2 by Materials Project

description: MgBi4(PO6)2 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent BiO5 square pyramids, corners with four PO4 tetrahedra, edges with two equivalent MgO6 octahedra, and an edgeedge with one PO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 2.06–2.21 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to five O2- atoms to form distorted BiO5 square pyramids that share corners with two equivalent MgO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–71°. There are a spread of Bi–O bond distances ranging from 2.09–2.57 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.25–3.03 Å. In the third Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.80 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.21–2.61 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 a cornercorner with one MgO6 octahedra, corners with two equivalent BiO5 square pyramids, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedral tilt angles are 17°. There are a spread of P–O bond distances ranging from 1.53–1.59 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent MgO6 octahedra and corners with two equivalent BiO5 square pyramids. The corner-sharing octahedra tilt angles range from 44–55°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Bi3+, and one P5+ atom. In the third O2- site, O2- is bonded in a T-shaped geometry to two equivalent Mg2+ and one P5+ atom. In the fourth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Bi3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Bi3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Bi3+ atoms. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Bi3+ and one P5+ atom. In the tenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Bi3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to two Bi3+ and one P5+ atom.