Materials Data on Mn4SiTeBr2O7 by Materials Project
Mn4SiTeO7Br2 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one Mn4SiTeO7Br2 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded in a 6-coordinate geometry to three O2- and three Br1- atoms. There are two shorter (2.11 Å) and one longer (2.81 Å) Mn–O bond lengths. There are a spread of Mn–Br bond distances ranging from 2.59–3.01 Å. In the second Mn2+ site, Mn2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Mn–O bond distances ranging from 2.09–2.41 Å. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent SiO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 2.17–2.36 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Si–O bond distances ranging from 1.65–1.67 Å. Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There is two shorter (1.92 Å) and one longer (1.94 Å) Te–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Mn2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mn2+ and one Te4+ atom. In the third O2- site, O2- is bonded to three Mn2+ and one Si4+ atom to form distorted edge-sharing OMn3Si tetrahedra. In the fourth O2- site, O2- is bonded to three Mn2+ and one Te4+ atom to form distorted OMn3Te trigonal pyramids that share a cornercorner with one OMn3Te trigonal pyramid, an edgeedge with one OMn3Si tetrahedra, and an edgeedge with one OMn3Te trigonal pyramid. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Mn2+ and one Si4+ atom. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 1-coordinate geometry to two equivalent Mn2+ atoms. In the second Br1- site, Br1- is bonded in a distorted single-bond geometry to one Mn2+ atom.