DOE OSTI2020
Tm2P4O13 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded to six O2- atoms to form TmO6 octahedra that share corners with six PO4 tetrahedra and an edgeedge with one TmO6 octahedra. There are a spread of Tm–O bond distances ranging from 2.16–2.33 Å. In the second Tm3+ site, Tm3+ is bonded to six O2- atoms to form TmO6 octahedra that share corners with six PO4 tetrahedra and an edgeedge with one TmO6 octahedra. There are a spread of Tm–O bond distances ranging from 2.12–2.33 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent TmO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 18–48°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four TmO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 6–56°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four TmO6 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–55°. There are a spread of P–O bond distances ranging from 1.51–1.61 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent TmO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–36°. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Tm3+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to one Tm3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Tm3+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Tm3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Tm3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Tm3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Tm3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Tm3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a linear geometry to one Tm3+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Tm3+ and one P5+ atom.