DOE OSTI2019
(NaBeB(PO4)2)6O2 crystallizes in the cubic P2_13 space group. The structure is three-dimensional and consists of four water molecules and one NaBeB(PO4)2 framework. In the NaBeB(PO4)2 framework, there are three inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are three shorter (2.68 Å) and three longer (2.70 Å) Na–O bond lengths. In the second Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with three equivalent BeO4 tetrahedra, corners with three equivalent BO4 tetrahedra, and corners with six PO4 tetrahedra. There are three shorter (2.84 Å) and three longer (2.94 Å) Na–O bond lengths. In the third Na site, Na is bonded to six O atoms to form distorted NaO6 octahedra that share corners with three equivalent BeO4 tetrahedra, corners with three equivalent BO4 tetrahedra, and corners with six PO4 tetrahedra. There are three shorter (2.86 Å) and three longer (2.93 Å) Na–O bond lengths. Be is bonded to four O atoms to form BeO4 tetrahedra that share corners with two NaO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 81°. There are a spread of Be–O bond distances ranging from 1.59–1.64 Å. B is bonded to four O atoms to form BO4 tetrahedra that share corners with two NaO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 67°. There is two shorter (1.46 Å) and two longer (1.48 Å) B–O bond length. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two NaO6 octahedra, corners with two equivalent BeO4 tetrahedra, and corners with two equivalent BO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–67°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two NaO6 octahedra, corners with two equivalent BeO4 tetrahedra, and corners with two equivalent BO4 tetrahedra. The corner-sharing octahedra tilt angles range from 60–66°. There are a spread of P–O bond distances ranging from 1.51–1.58 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to one Na, one B, and one P atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Be, and one P atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to one Na, one B, and one P atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one B and one P atom. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Be, and one P atom. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Be, and one P atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to one B and one P atom. In the eighth O site, O is bonded in a distorted bent 150 degrees geometry to one Na, one Be, and one P atom.