Materials Data on KNaTi2(PO5)2 by Materials Project
KNaTi2(PO5)2 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.74–3.17 Å. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.56–2.98 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–48°. There are a spread of Ti–O bond distances ranging from 1.77–2.18 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–48°. There are a spread of Ti–O bond distances ranging from 1.80–2.08 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 corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 45–50°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four TiO6 octahedra. The corner-sharing octahedra tilt angles range from 44–52°. There is one shorter (1.53 Å) and three longer (1.56 Å) P–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, and two Ti4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Ti4+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ti4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and two Ti4+ atoms. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Na1+, one Ti4+, and one P5+ atom.