Materials Data on Ba2Mg3Tl2(SnO3)4 by Materials Project

(BaMgTlSnO4)2Mg(SnO2)2 crystallizes in the tetragonal I4/mmm space group. The structure is two-dimensional and consists of two BaMgTlSnO4 sheets oriented in the (0, 0, 1) direction and two Mg(SnO2)2 sheets oriented in the (0, 0, 1) direction. In each BaMgTlSnO4 sheet, Ba2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are one shorter (2.34 Å) and four longer (3.05 Å) Ba–O bond lengths. Mg2+ is bonded in a distorted see-saw-like geometry to four equivalent O2- atoms. All Mg–O bond lengths are 2.20 Å. Tl1+ is bonded to six O2- atoms to form distorted TlO6 octahedra that share corners with four equivalent TlO6 octahedra, a cornercorner with one SnO5 trigonal bipyramid, and edges with eight equivalent TlO6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are a spread of Tl–O bond distances ranging from 2.34–3.35 Å. Sn3+ is bonded to five O2- atoms to form distorted SnO5 trigonal bipyramids that share a cornercorner with one TlO6 octahedra and corners with four equivalent SnO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.00 Å) and four longer (2.17 Å) Sn–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Sn3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Sn2 trigonal pyramids. In the second O2- site, O2- is bonded to one Ba2+ and five equivalent Tl1+ atoms to form a mixture of edge and corner-sharing OBaTl5 octahedra. The corner-sharing octahedral tilt angles are 6°. In the third O2- site, O2- is bonded in a 1-coordinate geometry to four equivalent Ba2+, one Tl1+, and one Sn3+ atom. In each Mg(SnO2)2 sheet, Mg2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Mg–O bond lengths are 2.58 Å. Sn3+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Sn–O bond lengths are 2.07 Å. O2- is bonded in a distorted see-saw-like geometry to two equivalent Mg2+ and two equivalent Sn3+ atoms.

(BaMgTlSnO₄)₂Mg(SnO₂)₂ 结晶于四方晶系I4/mmm空间群。该结构为二维层状结构，包含两片沿(0, 0, 1)方向取向的BaMgTlSnO₄原子层，以及两片沿(0, 0, 1)方向取向的Mg(SnO₂)₂原子层。在每一片BaMgTlSnO₄原子层中，Ba²⁺以五配位几何与五个O²⁻原子成键，Ba-O键存在1条较短键长（2.34 Å）与4条较长键长（3.05 Å）。Mg²⁺以畸变跷跷板型几何与四个等价的O²⁻原子成键，所有Mg-O键长均为2.20 Å。Tl⁺与六个O²⁻原子成键，形成畸变TlO₆八面体；该八面体与四个等价的TlO₆八面体共顶点，与一个SnO₅三角双锥共顶点，同时与八个等价的TlO₆八面体共边。共顶点八面体倾斜角为6°，Tl-O键长分布范围为2.34~3.35 Å。Sn³⁺与五个O²⁻原子成键，形成畸变SnO₅三角双锥；该三角双锥与一个TlO₆八面体共顶点，同时与四个等价的SnO₅三角双锥共顶点，共顶点八面体倾斜角为0°。Sn-O键存在1条较短键长（2.00 Å）与4条较长键长（2.17 Å）。体系中存在三个不等价的O²⁻位点：在第一个O²⁻位点中，O²⁻与两个等价的Mg²⁺及两个等价的Sn³⁺原子成键，形成兼具畸变共边与共顶点结构的OMg₂Sn₂三角锥；在第二个O²⁻位点中，O²⁻与一个Ba²⁺及五个等价的Tl⁺原子成键，形成兼具共边与共顶点结构的OBaTl₅八面体，其共顶点八面体倾斜角为6°；在第三个O²⁻位点中，O²⁻以单配位几何与四个等价的Ba²⁺、一个Tl⁺及一个Sn³⁺原子成键。在每一片Mg(SnO₂)₂原子层中，Mg²⁺以体心立方几何与八个等价的O²⁻原子成键，所有Mg-O键长均为2.58 Å；Sn³⁺以矩形跷跷板型几何与四个等价的O²⁻原子成键，所有Sn-O键长均为2.07 Å；O²⁻以畸变跷跷板型几何与两个等价的Mg²⁺及两个等价的Sn³⁺原子成键。