Materials Data on Mg2Fe7O12 by Materials Project

Mg2Fe7O12 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six FeO4 tetrahedra, an edgeedge with one MgO6 octahedra, and edges with five FeO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.09–2.11 Å. There are five inequivalent Fe+2.86+ sites. In the first Fe+2.86+ site, Fe+2.86+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four equivalent MgO6 octahedra and corners with eight FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is two shorter (1.92 Å) and two longer (1.97 Å) Fe–O bond length. In the second Fe+2.86+ site, Fe+2.86+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with four equivalent MgO6 octahedra and corners with eight FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Fe–O bond distances ranging from 1.92–1.97 Å. In the third Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four FeO6 octahedra. There are four shorter (2.13 Å) and two longer (2.14 Å) Fe–O bond lengths. In the fourth Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with three equivalent MgO6 octahedra, and edges with three FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.03–2.07 Å. In the fifth Fe+2.86+ site, Fe+2.86+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six FeO4 tetrahedra, edges with two equivalent MgO6 octahedra, and edges with four FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.04–2.08 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Fe+2.86+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms. In the fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg2+ and two Fe+2.86+ atoms. In the sixth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Fe+2.86+ atoms.

Mg₂Fe₇O₁₂ 为类尖晶石（Spinel-like）结构，结晶于单斜晶系C2/c空间群（monoclinic C2/c space group）。该结构为三维骨架结构。Mg²⁺与6个O²⁻配位形成MgO₆八面体（MgO₆ octahedra），该八面体与6个FeO₄四面体（FeO₄ tetrahedra）共享顶点，与1个MgO₆八面体共享一条棱，同时与5个FeO₆八面体（FeO₆ octahedra）共享多条棱。Mg—O键的键长分布范围为2.09~2.11 Å。

存在5个非等价的Fe².86⁺位点。在第一个Fe².86⁺位点中，Fe².86⁺与4个O²⁻配位形成FeO₄四面体，该四面体与4个等价的MgO₆八面体共享顶点，同时与8个FeO₆八面体共享顶点。顶点共享八面体的倾斜角范围为55°~59°。该位点的Fe—O键存在2条较短键长（1.92 Å）与2条较长键长（1.97 Å）。

在第二个Fe².86⁺位点中，Fe².86⁺与4个O²⁻配位形成FeO₄四面体，该四面体与4个等价的MgO₆八面体共享顶点，同时与8个FeO₆八面体共享顶点。顶点共享八面体的倾斜角范围为55°~58°。该位点的Fe—O键键长分布范围为1.92~1.97 Å。

在第三个Fe².86⁺位点中，Fe².86⁺与6个O²⁻配位形成FeO₆八面体，该八面体与6个FeO₄四面体共享顶点，与2个等价的MgO₆八面体共享棱，同时与4个FeO₆八面体共享多条棱。该位点的Fe—O键存在4条较短键长（2.13 Å）与2条较长键长（2.14 Å）。

在第四个Fe².86⁺位点中，Fe².86⁺与6个O²⁻配位形成FeO₆八面体，该八面体与6个FeO₄四面体共享顶点，与3个等价的MgO₆八面体共享棱，同时与3个FeO₆八面体共享多条棱。该位点的Fe—O键键长分布范围为2.03~2.07 Å。

在第五个Fe².86⁺位点中，Fe².86⁺与6个O²⁻配位形成FeO₆八面体，该八面体与6个FeO₄四面体共享顶点，与2个等价的MgO₆八面体共享棱，同时与4个FeO₆八面体共享多条棱。该位点的Fe—O键键长分布范围为2.04~2.08 Å。

存在6个非等价的O²⁻位点。在第一个O²⁻位点中，O²⁻以矩形跷跷板型配位几何（rectangular see-saw-like geometry）与4个Fe².86⁺离子配位。在第二个O²⁻位点中，O²⁻以矩形跷跷板型配位几何与1个Mg²⁺及3个Fe².86⁺离子配位。在第三个O²⁻位点中，O²⁻以畸变矩形跷跷板型配位几何与1个Mg²⁺及3个Fe².86⁺离子配位。在第四个O²⁻位点中，O²⁻以矩形跷跷板型配位几何与1个Mg²⁺及3个Fe².86⁺离子配位。在第五个O²⁻位点中，O²⁻以畸变矩形跷跷板型配位几何与2个等价的Mg²⁺及2个Fe².86⁺离子配位。在第六个O²⁻位点中，O²⁻以矩形跷跷板型配位几何与1个Mg²⁺及3个Fe².86⁺离子配位。