Materials Data on LiMn2P2O9 by Materials Project
LiMn2P2O9 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Li1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Li–O bond distances ranging from 2.14–2.37 Å. There are two inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with three equivalent PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Mn–O bond distances ranging from 1.90–1.99 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO6 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are four shorter (1.99 Å) and two longer (2.11 Å) Mn–O bond lengths. 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 five MnO6 octahedra. The corner-sharing octahedra tilt angles range from 20–51°. There is one shorter (1.53 Å) and three longer (1.55 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 two equivalent MnO6 octahedra and an edgeedge with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Li1+, one Mn+3.50+, and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Mn+3.50+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn+3.50+ and one P5+ atom. In the fifth O2- site, O2- is bonded in an L-shaped geometry to one Mn+3.50+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Li1+, one Mn+3.50+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn+3.50+ and one P5+ atom.