Materials Data on Fe3(AsO8)2 by Materials Project

Fe3(AsO8)2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two Fe3(AsO8)2 sheets oriented in the (0, 1, 0) direction. there are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent AsO4 tetrahedra. There is four shorter (1.90 Å) and two longer (1.92 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four equivalent AsO4 tetrahedra and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 1.89–2.08 Å. As is bonded to four O atoms to form AsO4 tetrahedra that share corners with five FeO6 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of As–O bond distances ranging from 1.70–1.76 Å. There are five inequivalent O sites. In the first O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the second O site, O is bonded in a distorted trigonal planar geometry to two equivalent Fe and one As atom. In the third O site, O is bonded in a bent 120 degrees geometry to one Fe and one As atom. In the fourth O site, O is bonded in a single-bond geometry to one Fe atom. In the fifth O site, O is bonded in a single-bond geometry to one Fe atom.

Fe₃(AsO₈)₂ 结晶于单斜晶系（monoclinic）C2/m空间群（space group）。该结构为二维结构，由两个沿(0,1,0)方向排列的Fe₃(AsO₈)₂层组成。存在两个不等价的Fe位点（site）：在第一个Fe位点中，Fe与六个O原子键合形成FeO₆八面体（octahedron），这些八面体与两个等价的AsO₄四面体（tetrahedron）共用顶点，其中包含四条较短的Fe–O键（键长1.90 Å）和两条较长的Fe–O键（键长1.92 Å）；第二个Fe位点中，Fe与六个O原子键合形成FeO₆八面体，这些八面体与四个等价的AsO₄四面体共用顶点，并与一个FeO₆八面体共用一条边，其Fe–O键长分布在1.89–2.08 Å范围内。As与四个O原子键合形成AsO₄四面体，这些四面体与五个FeO₆八面体共用顶点，共用顶点的八面体倾斜角范围为52–56°。此外存在五个不等价的O位点：第一个O位点中，O以120°弯曲构型与一个Fe原子和一个As原子键合；第二个O位点中，O以扭曲的三角平面构型与两个等价的Fe原子和一个As原子键合；第三个O位点中，O以120°弯曲构型与一个Fe原子和一个As原子键合；第四和第五个O位点中，O均以单键构型与一个Fe原子键合。