Materials Data on Ca2SiO4 by Materials Project

Ca2SiO4 is Ilmenite-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with eight CaO6 octahedra, corners with four equivalent SiO4 tetrahedra, edges with two equivalent CaO6 octahedra, and an edgeedge with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–70°. There are a spread of Ca–O bond distances ranging from 2.31–2.47 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with four equivalent CaO6 octahedra, corners with two equivalent SiO4 tetrahedra, edges with four CaO6 octahedra, and edges with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 62–70°. There are a spread of Ca–O bond distances ranging from 2.33–2.41 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six CaO6 octahedra and edges with three CaO6 octahedra. The corner-sharing octahedra tilt angles range from 50–61°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and one Si4+ atom.

硅酸二钙（Ca₂SiO₄）具有类钛铁矿结构，结晶于正交晶系Pnma空间群。其结构为三维网状结构。存在两个不等价的Ca²+位点。在第一个Ca²+位点中，Ca²+与六个O²-原子配位，形成畸变的CaO₆八面体，该八面体与八个CaO₆八面体共顶点、与四个等价的SiO₄四面体共顶点，与两个等价的CaO₆八面体共棱，还与一个SiO₄四面体共棱。共顶点的八面体倾斜角范围为54°至70°。Ca—O键长分布在2.31~2.47 Å之间。在第二个Ca²+位点中，Ca²+与六个O²-原子配位，形成CaO₆八面体，该八面体与四个等价的CaO₆八面体共顶点、与两个等价的SiO₄四面体共顶点，与四个CaO₆八面体共棱，还与两个等价的SiO₄四面体共棱。共顶点的八面体倾斜角范围为62°至70°。Ca—O键长分布在2.33~2.41 Å之间。Si⁴+与四个O²-原子配位，形成SiO₄四面体，该四面体与六个CaO₆八面体共顶点、与三个CaO₆八面体共棱。共顶点的八面体倾斜角范围为50°至61°。Si—O键长分布在1.64~1.67 Å之间。存在三个不等价的O²-位点。在第一个O²-位点中，O²-以畸变矩形跷跷板型配位几何与三个Ca²+和一个Si⁴+原子成键。在第二个O²-位点中，O²-以畸变矩形跷跷板型配位几何与三个Ca²+和一个Si⁴+原子成键。在第三个O²-位点中，O²-以四配位几何与三个Ca²+和一个Si⁴+原子成键。