Materials Data on Li2FeOF3 by Materials Project

Li2FeOF3 crystallizes in the monoclinic Pc space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to one O2- and five F1- atoms to form LiOF5 octahedra that share a cornercorner with one LiO2F4 octahedra, corners with four FeO2F4 octahedra, edges with two FeO2F4 octahedra, and edges with six LiO2F4 octahedra. The corner-sharing octahedra tilt angles range from 6–22°. The Li–O bond length is 2.20 Å. There are a spread of Li–F bond distances ranging from 2.02–2.29 Å. In the second Li1+ site, Li1+ is bonded to two O2- and four F1- atoms to form distorted LiO2F4 octahedra that share corners with four LiOF5 octahedra, edges with four FeO2F4 octahedra, and edges with five LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 4–24°. There are one shorter (2.03 Å) and one longer (2.09 Å) Li–O bond lengths. There are a spread of Li–F bond distances ranging from 1.97–2.45 Å. In the third Li1+ site, Li1+ is bonded to two O2- and four F1- atoms to form LiO2F4 octahedra that share corners with two equivalent LiO2F4 octahedra, corners with two FeO2F4 octahedra, edges with four FeO2F4 octahedra, and edges with five LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 3–24°. There are one shorter (2.01 Å) and one longer (2.32 Å) Li–O bond lengths. There are a spread of Li–F bond distances ranging from 1.99–2.46 Å. In the fourth Li1+ site, Li1+ is bonded to one O2- and five F1- atoms to form LiOF5 octahedra that share a cornercorner with one LiO2F4 octahedra, corners with four FeO2F4 octahedra, edges with two FeO2F4 octahedra, and edges with six LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 4–17°. The Li–O bond length is 2.15 Å. There are a spread of Li–F bond distances ranging from 2.03–2.17 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to two O2- and four F1- atoms to form FeO2F4 octahedra that share corners with five LiOF5 octahedra, edges with two equivalent FeO2F4 octahedra, and edges with six LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 6–13°. Both Fe–O bond lengths are 1.94 Å. There are a spread of Fe–F bond distances ranging from 1.99–2.13 Å. In the second Fe3+ site, Fe3+ is bonded to two O2- and four F1- atoms to form FeO2F4 octahedra that share corners with five LiOF5 octahedra, edges with two equivalent FeO2F4 octahedra, and edges with six LiOF5 octahedra. The corner-sharing octahedra tilt angles range from 3–22°. There is one shorter (1.92 Å) and one longer (1.95 Å) Fe–O bond length. There are a spread of Fe–F bond distances ranging from 2.01–2.11 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three Li1+ and two Fe3+ atoms to form OLi3Fe2 square pyramids that share corners with two equivalent FLi4Fe square pyramids, corners with two equivalent OLi3Fe2 trigonal bipyramids, edges with three FLi4Fe square pyramids, and an edgeedge with one OLi3Fe2 trigonal bipyramid. In the second O2- site, O2- is bonded to three Li1+ and two Fe3+ atoms to form distorted OLi3Fe2 trigonal bipyramids that share corners with two equivalent OLi3Fe2 square pyramids, corners with two equivalent FLi4Fe square pyramids, an edgeedge with one OLi3Fe2 square pyramid, and edges with three FLi4Fe square pyramids. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded to four Li1+ and one Fe3+ atom to form distorted FLi4Fe square pyramids that share corners with two equivalent FLi4Fe square pyramids, corners with two equivalent OLi3Fe2 trigonal bipyramids, an edgeedge with one FLi4Fe square pyramid, edges with two equivalent OLi3Fe2 square pyramids, and an edgeedge with one OLi3Fe2 trigonal bipyramid. In the second F1- site, F1- is bonded in a rectangular see-saw-like geometry to two Li1+ and two Fe3+ atoms. In the third F1- site, F1- is bonded in a rectangular see-saw-like geometry to two Li1+ and two Fe3+ atoms. In the fourth F1- site, F1- is bonded in a rectangular see-saw-like geometry to three Li1+ and one Fe3+ atom. In the fifth F1- site, F1- is bonded in a distorted see-saw-like geometry to three Li1+ and one Fe3+ atom. In the sixth F1- site, F1- is bonded to four Li1+ and one Fe3+ atom to form FLi4Fe square pyramids that share corners with two equivalent OLi3Fe2 square pyramids, corners with two equivalent FLi4Fe square pyramids, an edgeedge with one OLi3Fe2 square pyramid, an edgeedge with one FLi4Fe square pyramid, and edges with two equivalent OLi3Fe2 trigonal bipyramids.

Li₂FeOF₃结晶于单斜晶系Pc空间群，其结构为三维框架。体系中共存在4个非等效的Li⁺位点。在第一个Li⁺位点中，Li⁺与1个O²⁻和5个F⁻配位，形成LiOF₅八面体；该八面体与1个LiO₂F₄八面体共顶，与4个FeO₂F₄八面体共顶，与2个FeO₂F₄八面体共边，同时与6个LiO₂F₄八面体共边。共顶八面体的倾斜角范围为6°~22°，Li-O键长为2.20 Å，Li-F键长分布区间为2.02~2.29 Å。在第二个Li⁺位点中，Li⁺与2个O²⁻和4个F⁻配位，形成畸变的LiO₂F₄八面体；该八面体与4个LiOF₅八面体共顶，与4个FeO₂F₄八面体共边，同时与5个LiOF₅八面体共边。共顶八面体的倾斜角范围为4°~24°，存在1条较短的Li-O键（2.03 Å）与1条较长的Li-O键（2.09 Å），Li-F键长分布区间为1.97~2.45 Å。在第三个Li⁺位点中，Li⁺与2个O²⁻和4个F⁻配位，形成LiO₂F₄八面体；该八面体与2个等价的LiO₂F₄八面体共顶，与2个FeO₂F₄八面体共顶，与4个FeO₂F₄八面体共边，同时与5个LiOF₅八面体共边。共顶八面体的倾斜角范围为3°~24°，存在1条较短的Li-O键（2.01 Å）与1条较长的Li-O键（2.32 Å），Li-F键长分布区间为1.99~2.46 Å。在第四个Li⁺位点中，Li⁺与1个O²⁻和5个F⁻配位，形成LiOF₅八面体；该八面体与1个LiO₂F₄八面体共顶，与4个FeO₂F₄八面体共顶，与2个FeO₂F₄八面体共边，同时与6个LiO₂F₄八面体共边。共顶八面体的倾斜角范围为4°~17°，Li-O键长为2.15 Å，Li-F键长分布区间为2.03~2.17 Å。

体系中共存在2个非等效的Fe³⁺位点。在第一个Fe³⁺位点中，Fe³⁺与2个O²⁻和4个F⁻配位，形成FeO₂F₄八面体；该八面体与5个LiOF₅八面体共顶，与2个等价的FeO₂F₄八面体共边，同时与6个LiOF₅八面体共边。共顶八面体的倾斜角范围为6°~13°，两条Fe-O键长均为1.94 Å，Fe-F键长分布区间为1.99~2.13 Å。在第二个Fe³⁺位点中，Fe³⁺与2个O²⁻和4个F⁻配位，形成FeO₂F₄八面体；该八面体与5个LiOF₅八面体共顶，与2个等价的FeO₂F₄八面体共边，同时与6个LiOF₅八面体共边。共顶八面体的倾斜角范围为3°~22°，存在1条较短的Fe-O键（1.92 Å）与1条较长的Fe-O键（1.95 Å），Fe-F键长分布区间为2.01~2.11 Å。

体系中共存在2个非等效的O²⁻位点。在第一个O²⁻位点中，O²⁻与3个Li⁺和2个Fe³⁺配位，形成OLi₃Fe₂四方锥；该四方锥与2个等价的FLi₄Fe四方锥共顶，与2个等价的OLi₃Fe₂三角双锥共顶，与3个FLi₄Fe四方锥共边，同时与1个OLi₃Fe₂三角双锥共边。在第二个O²⁻位点中，O²⁻与3个Li⁺和2个Fe³⁺配位，形成畸变的OLi₃Fe₂三角双锥；该三角双锥与2个等价的OLi₃Fe₂四方锥共顶，与2个等价的FLi₄Fe四方锥共顶，与1个OLi₃Fe₂四方锥共边，同时与3个FLi₄Fe四方锥共边。

体系中共存在6个非等效的F⁻位点。在第一个F⁻位点中，F⁻与4个Li⁺和1个Fe³⁺配位，形成畸变的FLi₄Fe四方锥；该四方锥与2个等价的FLi₄Fe四方锥共顶，与2个等价的OLi₃Fe₂三角双锥共顶，与1个FLi₄Fe四方锥共边，与2个等价的OLi₃Fe₂四方锥共边，同时与1个OLi₃Fe₂三角双锥共边。在第二个F⁻位点中，F⁻以矩形跷跷板型配位几何与2个Li⁺和2个Fe³⁺配位。在第三个F⁻位点中，F⁻以矩形跷跷板型配位几何与2个Li⁺和2个Fe³⁺配位。在第四个F⁻位点中，F⁻以矩形跷跷板型配位几何与3个Li⁺和1个Fe³⁺配位。在第五个F⁻位点中，F⁻以畸变跷跷板型配位几何与3个Li⁺和1个Fe³⁺配位。在第六个F⁻位点中，F⁻与4个Li⁺和1个Fe³⁺配位，形成FLi₄Fe四方锥；该四方锥与2个等价的OLi₃Fe₂四方锥共顶，与2个等价的FLi₄Fe四方锥共顶，与1个OLi₃Fe₂四方锥共边，与1个FLi₄Fe四方锥共边，同时与2个等价的OLi₃Fe₂三角双锥共边。