DOE OSTI2020
MnAlP(HO3)2H2O crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional and consists of eight water molecules and one MnAlP(HO3)2 framework. In the MnAlP(HO3)2 framework, Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent PO4 tetrahedra and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.14–2.38 Å. Al3+ is bonded in a distorted square co-planar geometry to four O2- atoms. There is two shorter (1.80 Å) and two longer (1.88 Å) Al–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent MnO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There is two shorter (1.54 Å) and two longer (1.57 Å) P–O bond length. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Al3+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Al3+ and one P5+ atom.