Materials Data on Ba2YTlSn2O7 by Materials Project
Ba2YTlSn2O7 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are one shorter (2.45 Å) and four longer (3.01 Å) Ba–O bond lengths. Y3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Y–O bond lengths are 2.55 Å. Tl1+ is bonded to six O2- atoms to form TlO6 octahedra that share corners with four equivalent TlO6 octahedra, corners with two equivalent SnO5 square pyramids, and edges with four equivalent TlO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.76 Å) and four longer (3.00 Å) Tl–O bond lengths. Sn3+ is bonded to five O2- atoms to form SnO5 square pyramids that share a cornercorner with one TlO6 octahedra and corners with four equivalent SnO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.05 Å) and four longer (2.14 Å) Sn–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+, one Tl1+, and one Sn3+ atom to form distorted OBa4TlSn octahedra that share corners with five equivalent OBa4TlSn octahedra and edges with eight OBa2Tl4 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. In the second O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Y3+ and two equivalent Sn3+ atoms. In the third O2- site, O2- is bonded to two equivalent Ba2+ and four equivalent Tl1+ atoms to form a mixture of edge and corner-sharing OBa2Tl4 octahedra. The corner-sharing octahedral tilt angles are 0°.