Materials Data on Li2FeNi3O8 by Materials Project

Li2FeNi3O8 is Spinel-derived structured and crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with nine NiO6 octahedra. The corner-sharing octahedra tilt angles range from 56–64°. There are a spread of Li–O bond distances ranging from 1.92–2.01 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with three equivalent FeO6 octahedra, corners with three NiO6 octahedra, and edges with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 59–67°. There are a spread of Li–O bond distances ranging from 1.76–1.90 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six NiO6 octahedra, corners with three equivalent LiO4 tetrahedra, corners with three equivalent LiO4 trigonal pyramids, and edges with three NiO6 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Fe–O bond distances ranging from 1.98–2.11 Å. There are three inequivalent Ni+3.67+ sites. In the first Ni+3.67+ site, Ni+3.67+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one FeO6 octahedra, edges with four NiO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Ni–O bond distances ranging from 1.86–1.93 Å. In the second Ni+3.67+ site, Ni+3.67+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one FeO6 octahedra, edges with four NiO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 51–53°. There are a spread of Ni–O bond distances ranging from 1.86–1.94 Å. In the third Ni+3.67+ site, Ni+3.67+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with three equivalent LiO4 tetrahedra, a cornercorner with one LiO4 trigonal pyramid, an edgeedge with one FeO6 octahedra, edges with four NiO6 octahedra, and an edgeedge with one LiO4 trigonal pyramid. The corner-sharing octahedral tilt angles are 54°. There are a spread of Ni–O bond distances ranging from 1.92–2.04 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Li1+, one Fe3+, and two Ni+3.67+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Fe3+, and two Ni+3.67+ atoms. In the third O2- site, O2- is bonded to one Li1+, one Fe3+, and two Ni+3.67+ atoms to form distorted OLiFeNi2 tetrahedra that share corners with four OLiNi3 tetrahedra and edges with two OLiFeNi2 tetrahedra. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+ and three Ni+3.67+ atoms. In the fifth O2- site, O2- is bonded to one Li1+ and three Ni+3.67+ atoms to form distorted corner-sharing OLiNi3 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Fe3+, and two Ni+3.67+ atoms. In the seventh O2- site, O2- is bonded to one Li1+, one Fe3+, and two Ni+3.67+ atoms to form a mixture of distorted edge and corner-sharing OLiFeNi2 tetrahedra. In the eighth O2- site, O2- is bonded to one Li1+, one Fe3+, and two Ni+3.67+ atoms to form a mixture of distorted edge and corner-sharing OLiFeNi2 tetrahedra.

Li₂FeNi₃O₈为尖晶石衍生（Spinel-derived）结构，结晶于单斜晶系Cc空间群（monoclinic Cc space group）。该结构为三维网状结构。存在两种不等价的Li⁺位点。在第一个Li⁺位点中，Li⁺与四个O²⁻原子配位，形成LiO₄四面体（LiO₄ tetrahedra），该四面体与三个等价的FeO₆八面体（FeO₆ octahedra）以及九个等价的NiO₆八面体（NiO₆ octahedra）通过共用顶点相连。共顶点八面体的倾斜角范围为56°~64°。Li-O键长分布区间为1.92~2.01 Å。
在第二个Li⁺位点中，Li⁺与四个O²⁻原子配位，形成畸变的LiO₄三角锥（LiO₄ trigonal pyramids），该三角锥与三个等价的FeO₆八面体、三个NiO₆八面体共用顶点，并与三个NiO₆八面体共用边。共顶点八面体的倾斜角范围为59°~67°。Li-O键长分布区间为1.76~1.90 Å。
Fe³⁺与六个O²⁻原子配位，形成FeO₆八面体（FeO₆ octahedra），该八面体与六个NiO₆八面体共用顶点，与三个等价的LiO₄四面体、三个等价的LiO₄三角锥共用顶点，并与三个NiO₆八面体共用边。共顶点八面体的倾斜角范围为51°~54°。Fe-O键长分布区间为1.98~2.11 Å。
存在三种不等价的Ni^(3.67+)位点。在第一个Ni^(3.67+)位点中，Ni^(3.67+)与六个O²⁻原子配位，形成NiO₆八面体（NiO₆ octahedra），该八面体与两个等价的FeO₆八面体共用顶点，与三个等价的LiO₄四面体共用顶点，与一个LiO₄三角锥形成共顶点连接，与一个FeO₆八面体形成共边连接，与四个NiO₆八面体共用边，并与一个LiO₄三角锥形成共边连接。共顶点八面体的倾斜角范围为52°~53°。Ni-O键长分布区间为1.86~1.93 Å。
在第二个Ni^(3.67+)位点中，Ni^(3.67+)与六个O²⁻原子配位，形成NiO₆八面体（NiO₆ octahedra），该八面体与两个等价的FeO₆八面体共用顶点，与三个等价的LiO₄四面体共用顶点，与一个LiO₄三角锥形成共顶点连接，与一个FeO₆八面体形成共边连接，与四个NiO₆八面体共用边，并与一个LiO₄三角锥形成共边连接。共顶点八面体的倾斜角范围为51°~53°。Ni-O键长分布区间为1.86~1.94 Å。
在第三个Ni^(3.67+)位点中，Ni^(3.67+)与六个O²⁻原子配位，形成NiO₆八面体（NiO₆ octahedra），该八面体与两个等价的FeO₆八面体共用顶点，与三个等价的LiO₄四面体共用顶点，与一个LiO₄三角锥形成共顶点连接，与一个FeO₆八面体形成共边连接，与四个NiO₆八面体共用边，并与一个LiO₄三角锥形成共边连接。共顶点八面体的倾斜角为54°。Ni-O键长分布区间为1.92~2.04 Å。
存在八种不等价的O²⁻位点。在第一个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，配位几何为矩形跷跷板型（rectangular see-saw-like geometry）。在第二个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，配位几何为畸变矩形跷跷板型。在第三个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，形成畸变的OLiFeNi₂四面体，该四面体与四个OLiNi₃四面体共用顶点，并与两个OLiFeNi₂四面体共用边。在第四个O²⁻位点中，O²⁻与一个Li⁺以及三个Ni^(3.67+)原子配位，配位几何为畸变矩形跷跷板型。在第五个O²⁻位点中，O²⁻与一个Li⁺以及三个Ni^(3.67+)原子配位，形成畸变的共顶点OLiNi₃四面体。在第六个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，配位几何为畸变矩形跷跷板型。在第七个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，形成兼具畸变边共享与顶点共享特征的OLiFeNi₂四面体。在第八个O²⁻位点中，O²⁻与一个Li⁺、一个Fe³⁺以及两个Ni^(3.67+)原子配位，形成兼具畸变边共享与顶点共享特征的OLiFeNi₂四面体。