DOI: 10.17188/1323768
title: Materials Data on MgAg2P2O9 by Materials Project

description: MgAg2P2O9 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.14–2.38 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six AgO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.16–2.37 Å. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with four AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–69°. There are a spread of Mg–O bond distances ranging from 2.15–2.38 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with six AgO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–69°. There are a spread of Mg–O bond distances ranging from 2.16–2.37 Å. There are six inequivalent Ag3+ sites. In the first Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 pentagonal pyramids that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.03–2.27 Å. In the second Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.03–2.27 Å. In the third Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.04–2.26 Å. In the fourth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, corners with three PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–63°. There are a spread of Ag–O bond distances ranging from 2.04–2.25 Å. In the fifth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share a cornercorner with one AgO6 octahedra, corners with two MgO6 octahedra, a cornercorner with one AgO6 pentagonal pyramid, corners with four PO4 tetrahedra, and edges with two equivalent AgO6 octahedra. The corner-sharing octahedra tilt angles range from 57–69°. There are a spread of Ag–O bond distances ranging from 2.04–2.66 Å. In the sixth Ag3+ site, Ag3+ is bonded to six O2- atoms to form distorted AgO6 octahedra that share corners with two MgO6 octahedra, corners with two AgO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent AgO6 octahedra. The corner-sharing octahedra tilt angles range from 57–69°. There are a spread of Ag–O bond distances ranging from 2.04–2.65 Å. There are eight inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three AgO6 octahedra, corners with two equivalent AgO6 pentagonal pyramids, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–52°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four AgO6 octahedra, a cornercorner with one AgO6 pentagonal pyramid, and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five AgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–53°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five AgO6 octahedra and an edgeedge with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–53°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 28–59°. There are a spread of P–O bond distances ranging from 1.54–1.61 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 29–59°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 28–59°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AgO6 octahedra, corners with four MgO6 octahedra, and an edgeedge with one AgO6 octahedra. The corner-sharing octahedra tilt angles range from 29–59°. There are a spread of P–O bond distances ranging from 1.54–1.61 Å. There are twenty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ag3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to three Ag3+ atoms. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the eighteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ag3+ and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ag3+, and one P5+ atom.