Materials Data on Li2FePO4F by Materials Project

Li2FePO4F crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- and one F1- atom to form distorted LiO4F trigonal bipyramids that share corners with two equivalent FeO4F2 octahedra, corners with two PO4 tetrahedra, an edgeedge with one LiO4F2 octahedra, edges with two equivalent FeO4F2 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–55°. There are a spread of Li–O bond distances ranging from 1.99–2.27 Å. The Li–F bond length is 1.89 Å. In the second Li1+ site, Li1+ is bonded in a 6-coordinate geometry to five O2- and one F1- atom. There are a spread of Li–O bond distances ranging from 1.96–2.43 Å. The Li–F bond length is 2.33 Å. In the third Li1+ site, Li1+ is bonded to four O2- and two F1- atoms to form distorted LiO4F2 octahedra that share corners with two equivalent FeO4F2 octahedra, corners with four PO4 tetrahedra, an edgeedge with one LiO4F trigonal bipyramid, and faces with two equivalent FeO4F2 octahedra. The corner-sharing octahedra tilt angles range from 35–44°. There are a spread of Li–O bond distances ranging from 2.09–2.37 Å. There is one shorter (1.91 Å) and one longer (2.01 Å) Li–F bond length. In the fourth Li1+ site, Li1+ is bonded in a 5-coordinate geometry to four O2- and one F1- atom. There are a spread of Li–O bond distances ranging from 1.91–2.39 Å. The Li–F bond length is 1.88 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four O2- and two F1- atoms to form FeO4F2 octahedra that share corners with two equivalent LiO4F2 octahedra, corners with two equivalent FeO4F2 octahedra, corners with four PO4 tetrahedra, and edges with two equivalent LiO4F trigonal bipyramids. The corner-sharing octahedra tilt angles range from 35–59°. There are a spread of Fe–O bond distances ranging from 2.10–2.18 Å. There are one shorter (2.13 Å) and one longer (2.22 Å) Fe–F bond lengths. In the second Fe2+ site, Fe2+ is bonded to four O2- and two F1- atoms to form FeO4F2 octahedra that share corners with two equivalent FeO4F2 octahedra, corners with four PO4 tetrahedra, corners with two equivalent LiO4F trigonal bipyramids, and faces with two equivalent LiO4F2 octahedra. The corner-sharing octahedral tilt angles are 59°. There are a spread of Fe–O bond distances ranging from 2.06–2.26 Å. There are one shorter (2.10 Å) and one longer (2.19 Å) Fe–F bond lengths. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent LiO4F2 octahedra, corners with four FeO4F2 octahedra, a cornercorner with one LiO4F trigonal bipyramid, and an edgeedge with one LiO4F trigonal bipyramid. The corner-sharing octahedra tilt angles range from 23–55°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent LiO4F2 octahedra, corners with four FeO4F2 octahedra, and a cornercorner with one LiO4F trigonal bipyramid. The corner-sharing octahedra tilt angles range from 25–54°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+, one Fe2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one Fe2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Li1+, one Fe2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Li1+, one Fe2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted see-saw-like geometry to two Li1+, one Fe2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Li1+, one Fe2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to two Li1+, one Fe2+, and one P5+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a 5-coordinate geometry to three Li1+ and two Fe2+ atoms. In the second F1- site, F1- is bonded in a distorted see-saw-like geometry to two Li1+ and two Fe2+ atoms.

磷酸氟铁锂（Li₂FePO₄F）结晶于三斜晶系（triclinic）P1空间群（space group），其晶体结构为三维网状结构。体系中存在4个不等价的Li⁺配位位点。在第一个Li⁺位点中，Li⁺与4个O²⁻和1个F⁻原子配位，形成畸变LiO₄F三角双锥（trigonal bipyramid）配位多面体，该多面体与2个等价的FeO₄F₂八面体（octahedron）共享顶角、与2个PO₄四面体（tetrahedron）共享顶角、与1个LiO₄F₂八面体共享一条棱、与2个等价的FeO₄F₂八面体共享多条棱、与1个PO₄四面体共享一条棱。共享顶角的八面体倾斜角范围为42°~55°。Li—O键长分布在1.99~2.27 Å之间，Li—F键长为1.89 Å。在第二个Li⁺位点中，Li⁺采取6配位构型，与5个O²⁻和1个F⁻原子配位。Li—O键长分布在1.96~2.43 Å之间，Li—F键长为2.33 Å。在第三个Li⁺位点中，Li⁺与4个O²⁻和2个F⁻原子配位，形成畸变LiO₄F₂八面体配位多面体，该多面体与2个等价的FeO₄F₂八面体共享顶角、与4个PO₄四面体共享顶角、与1个LiO₄F三角双锥共享一条棱、与2个等价的FeO₄F₂八面体共享多个面。共享顶角的八面体倾斜角范围为35°~44°。Li—O键长分布在2.09~2.37 Å之间，存在1条较短的Li—F键（1.91 Å）与1条较长的Li—F键（2.01 Å）。在第四个Li⁺位点中，Li⁺采取5配位构型，与4个O²⁻和1个F⁻原子配位。Li—O键长分布在1.91~2.39 Å之间，Li—F键长为1.88 Å。体系中存在2个不等价的Fe²+配位位点。在第一个Fe²+位点中，Fe²+与4个O²⁻和2个F⁻原子配位，形成FeO₄F₂八面体配位多面体，该多面体与2个等价的LiO₄F₂八面体共享顶角、与2个等价的FeO₄F₂八面体共享顶角、与4个PO₄四面体共享顶角、与2个等价的LiO₄F三角双锥共享多条棱。共享顶角的八面体倾斜角范围为35°~59°。Fe—O键长分布在2.10~2.18 Å之间，存在1条较短的Fe—F键（2.13 Å）与1条较长的Fe—F键（2.22 Å）。在第二个Fe²+位点中，Fe²+与4个O²⁻和2个F⁻原子配位，形成FeO₄F₂八面体配位多面体，该多面体与2个等价的FeO₄F₂八面体共享顶角、与4个PO₄四面体共享顶角、与2个等价的LiO₄F三角双锥共享顶角、与2个等价的LiO₄F₂八面体共享多个面。共享顶角的八面体倾斜角为59°。Fe—O键长分布在2.06~2.26 Å之间，存在1条较短的Fe—F键（2.10 Å）与1条较长的Fe—F键（2.19 Å）。体系中存在2个不等价的P⁵+配位位点。在第一个P⁵+位点中，P⁵+与4个O²⁻原子配位，形成PO₄四面体配位多面体，该多面体与2个等价的LiO₄F₂八面体共享顶角、与4个FeO₄F₂八面体共享顶角、与1个LiO₄F三角双锥共享一个顶角、与1个LiO₄F三角双锥共享一条棱。共享顶角的八面体倾斜角范围为23°~55°。P—O键长分布在1.54~1.58 Å之间。在第二个P⁵+位点中，P⁵+与4个O²⁻原子配位，形成PO₄四面体配位多面体，该多面体与2个等价的LiO₄F₂八面体共享顶角、与4个FeO₄F₂八面体共享顶角、与1个LiO₄F三角双锥共享一个顶角。共享顶角的八面体倾斜角范围为25°~54°。存在2条较短的P—O键（1.55 Å）与2条较长的P—O键（1.56 Å）。体系中存在8个不等价的O²⁻配位位点。在第一个O²⁻位点中，O²⁻采取4配位构型，与2个Li⁺、1个Fe²+和1个P⁵+原子配位。在第二个O²⁻位点中，O²⁻采取3配位构型，与1个Li⁺、1个Fe²+和1个P⁵+原子配位。在第三个O²⁻位点中，O²⁻采取5配位构型，与3个Li⁺、1个Fe²+和1个P⁵+原子配位。在第四个O²⁻位点中，O²⁻采取矩形跷跷板状（rectangular see-saw-like）配位几何，与2个Li⁺、1个Fe²+和1个P⁵+原子配位。在第五个O²⁻位点中，O²⁻采取5配位构型，与3个Li⁺、1个Fe²+和1个P⁵+原子配位。在第六个O²⁻位点中，O²⁻采取畸变跷跷板状（distorted see-saw-like）配位几何，与2个Li⁺、1个Fe²+和1个P⁵+原子配位。在第七个O²⁻位点中，O²⁻采取畸变矩形跷跷板状（distorted rectangular see-saw-like）配位几何，与2个Li⁺、1个Fe²+和1个P⁵+原子配位。在第八个O²⁻位点中，O²⁻采取4配位构型，与2个Li⁺、1个Fe²+和1个P⁵+原子配位。体系中存在2个不等价的F⁻配位位点。在第一个F⁻位点中，F⁻采取5配位构型，与3个Li⁺和2个Fe²+原子配位。在第二个F⁻位点中，F⁻采取畸变跷跷板状配位几何，与2个Li⁺和2个Fe²+原子配位。