Materials Data on Ta5Zn7O18 by Materials Project
Ta5Zn7O18 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Ta+4.40+ sites. In the first Ta+4.40+ site, Ta+4.40+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with three equivalent ZnO4 tetrahedra, and edges with two equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 28–48°. There are a spread of Ta–O bond distances ranging from 1.90–2.20 Å. In the second Ta+4.40+ site, Ta+4.40+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four ZnO4 tetrahedra and edges with two equivalent TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.92–2.12 Å. In the third Ta+4.40+ site, Ta+4.40+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with four equivalent TaO6 octahedra and corners with four ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–48°. There are a spread of Ta–O bond distances ranging from 2.00–2.06 Å. There are four inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Zn–O bond distances ranging from 1.97–2.15 Å. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with seven TaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are a spread of Zn–O bond distances ranging from 1.97–2.12 Å. In the third Zn2+ site, Zn2+ is bonded to four O2- atoms to form distorted ZnO4 tetrahedra that share corners with four TaO6 octahedra and corners with two equivalent ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–67°. All Zn–O bond lengths are 2.02 Å. In the fourth Zn2+ site, Zn2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Zn–O bond distances ranging from 2.01–2.57 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to one Ta+4.40+ and two Zn2+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two Ta+4.40+ and two Zn2+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta+4.40+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ta+4.40+ and two equivalent Zn2+ atoms. In the fifth O2- site, O2- is bonded to two Ta+4.40+ and two equivalent Zn2+ atoms to form distorted OTa2Zn2 tetrahedra that share corners with two equivalent OTaZn3 tetrahedra and an edgeedge with one OTa2Zn2 tetrahedra. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to two Ta+4.40+ and one Zn2+ atom. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Ta+4.40+ and two equivalent Zn2+ atoms. In the eighth O2- site, O2- is bonded to one Ta+4.40+ and three Zn2+ atoms to form corner-sharing OTaZn3 tetrahedra. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ta+4.40+ and one Zn2+ atom.