DOE OSTI2020
Bi6ZnO7(PO4)2 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Zn2+ is bonded to four O2- atoms to form distorted ZnO4 trigonal pyramids that share corners with two equivalent PO4 tetrahedra. There are a spread of Zn–O bond distances ranging from 1.90–2.12 Å. There are six inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.92 Å. In the second Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.25–2.94 Å. In the third Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.14–2.64 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 8-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.74 Å. In the fifth Bi3+ site, Bi3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.88 Å. In the sixth Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.60 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 two equivalent ZnO4 trigonal pyramids. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Zn2+ and two Bi3+ atoms. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two Bi3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three Bi3+ and one P5+ atom. In the fifth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the sixth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Zn2+, two Bi3+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Bi3+ and one P5+ atom. In the tenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted edge and corner-sharing OBi4 tetrahedra. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Zn2+ and two Bi3+ atoms. In the twelfth O2- site, O2- is bonded in a distorted single-bond geometry to two Bi3+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Bi3+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the fifteenth O2- site, O2- is bonded in a single-bond geometry to two Bi3+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zn2+, one Bi3+, and one P5+ atom.