DOI: 10.17188/1749336
title: Materials Data on BaLiMg2AlSi3(O5F)2 by Materials Project

description: LiBaMg2AlSi3(O5F)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. Li1+ is bonded to four O2- and two F1- atoms to form LiO4F2 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, and edges with six MgO4F2 octahedra. There are a spread of Li–O bond distances ranging from 2.00–2.22 Å. There are one shorter (2.09 Å) and one longer (2.16 Å) Li–F bond lengths. Ba2+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of Ba–O bond distances ranging from 2.80–3.38 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form MgO4F2 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, edges with three equivalent LiO4F2 octahedra, and edges with three equivalent MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.01–2.13 Å. There are one shorter (2.03 Å) and one longer (2.04 Å) Mg–F bond lengths. In the second Mg2+ site, Mg2+ is bonded to four O2- and two F1- atoms to form MgO4F2 octahedra that share a cornercorner with one AlO4 tetrahedra, corners with three SiO4 tetrahedra, edges with three equivalent LiO4F2 octahedra, and edges with three equivalent MgO4F2 octahedra. There are a spread of Mg–O bond distances ranging from 2.00–2.12 Å. There are one shorter (2.04 Å) and one longer (2.07 Å) Mg–F bond lengths. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one LiO4F2 octahedra, corners with two MgO4F2 octahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–63°. There are a spread of Al–O bond distances ranging from 1.70–1.78 Å. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO4F2 octahedra, corners with two MgO4F2 octahedra, and corners with three equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is one shorter (1.61 Å) and three longer (1.65 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO4F2 octahedra, corners with two MgO4F2 octahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–58°. There is one shorter (1.58 Å) and three longer (1.68 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share a cornercorner with one LiO4F2 octahedra, corners with two MgO4F2 octahedra, and corners with three equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is one shorter (1.59 Å) and three longer (1.68 Å) Si–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Al3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Si4+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+, one Al3+, and one Si4+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Si4+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Si4+ atoms. In the seventh O2- site, O2- is bonded in a distorted tetrahedral geometry to one Li1+, two Mg2+, and one Al3+ atom. In the eighth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Mg2+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, two Mg2+, and one Si4+ atom. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, two Mg2+, and one Si4+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to one Li1+ and two Mg2+ atoms. In the second F1- site, F1- is bonded in a distorted T-shaped geometry to one Li1+ and two Mg2+ atoms.