Materials Data on Ta2Zn4O9 by Materials Project
Zn4Ta2O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with six ZnO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Ta–O bond distances ranging from 1.96–2.03 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two TaO6 octahedra, corners with three ZnO4 tetrahedra, a cornercorner with one ZnO5 trigonal bipyramid, and edges with two TaO6 octahedra. The corner-sharing octahedra tilt angles range from 34–38°. There are a spread of Ta–O bond distances ranging from 1.91–2.14 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four ZnO4 tetrahedra, and edges with two equivalent ZnO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 34°. There are four shorter (2.00 Å) and two longer (2.01 Å) Ta–O bond lengths. In the fourth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with five ZnO4 tetrahedra, corners with two equivalent ZnO5 trigonal bipyramids, and an edgeedge with one TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.90–2.26 Å. In the fifth Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six ZnO4 tetrahedra, a cornercorner with one ZnO5 trigonal bipyramid, and an edgeedge with one TaO6 octahedra. There are a spread of Ta–O bond distances ranging from 1.92–2.19 Å. There are eight inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with six TaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, a cornercorner with one ZnO5 trigonal bipyramid, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 51–64°. There are a spread of Zn–O bond distances ranging from 1.93–2.11 Å. In the second Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with four TaO6 octahedra, corners with two ZnO4 tetrahedra, and a cornercorner with one ZnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 49–66°. There are a spread of Zn–O bond distances ranging from 1.96–2.09 Å. In the third Zn2+ site, Zn2+ is bonded to four O2- atoms to form ZnO4 tetrahedra that share corners with five TaO6 octahedra, a cornercorner with one ZnO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 34–65°. There are a spread of Zn–O bond distances ranging from 1.95–2.02 Å. In the fourth 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 1.93–2.11 Å. In the fifth 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 2.00–2.25 Å. In the sixth 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 1.95–2.06 Å. In the seventh Zn2+ site, Zn2+ is bonded to five O2- atoms to form distorted ZnO5 trigonal bipyramids that share corners with four TaO6 octahedra, corners with two ZnO4 tetrahedra, an edgeedge with one TaO6 octahedra, and an edgeedge with one ZnO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 40–56°. There are a spread of Zn–O bond distances ranging from 1.99–2.26 Å. In the eighth Zn2+ site, Zn2+ is bonded to four O2- atoms to form distorted ZnO4 tetrahedra that share corners with four TaO6 octahedra, corners with two ZnO4 tetrahedra, and an edgeedge with one ZnO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–65°. There are a spread of Zn–O bond distances ranging from 1.95–2.03 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ta5+ and two Zn2+ atoms. In the third O2- site, O2- is bonded to two Ta5+ and two equivalent Zn2+ atoms to form distorted OTa2Zn2 tetrahedra that share corners with two equivalent OTaZn3 tetrahedra, a cornercorner with one OTa2Zn2 trigonal pyramid, and an edgeedge with one OTa2Zn2 tetrahedra. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two Ta5+ and one Zn2+ atom. In the fifth O2- site, O2- is bonded to two Ta5+ and two equivalent Zn2+ atoms to form a mixture of distorted edge and corner-sharing OTa2Zn2 trigonal pyramids. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Ta5+ and two Zn2+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Ta5+ and one Zn2+ atom. In the eighth O2- site, O2- is bonded to one Ta5+ and three Zn2+ atoms to form a mixture of distorted edge and corner-sharing OTaZn3 tetrahedra. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Zn2+ atoms. In the tenth O2- site, O2- is bonded in a distorted T-shaped geometry to one Ta5+ and two equivalent Zn2+ atoms. In the eleventh O2- site, O2- is bonded in a trigonal planar geometry to one Ta5+ and two Zn2+ atoms. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to two Ta5+ and one Zn2+ atom. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ta5+ and two equivalent Zn2+ atoms. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Zn2+ atoms. In the fifteenth O2- site, O2- is bonded to one Ta5+ and three Zn2+ atoms to form corner-sharing OTaZn3 tetrahedra. In the sixteenth O2- site, O2- is bonded in a trigonal planar geometry to one Ta5+ and two Zn2+ atoms. In the seventeenth O2- site, O2- is bonded to one Ta5+ and three Zn2+ atoms to form a mixture of distorted edge and corner-sharing OTaZn3 tetrahedra. In the eighteenth O2- site, O2- is bonded in a trigonal planar geometry to one Ta5+ and two Zn2+ atoms.