Materials Data on Ca3SiO4F by Materials Project

Ca3SiO4F is Ilmenite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded in a 6-coordinate geometry to four O and two equivalent F atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.54 Å. There are one shorter (2.38 Å) and one longer (2.65 Å) Ca–F bond lengths. In the second Ca site, Ca is bonded in a 6-coordinate geometry to four O and two equivalent F atoms. There are a spread of Ca–O bond distances ranging from 2.28–2.43 Å. There are one shorter (2.48 Å) and one longer (2.57 Å) Ca–F bond lengths. Si is bonded in a tetrahedral geometry to four O atoms. There is one shorter (1.67 Å) and three longer (1.68 Å) Si–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to three Ca and one Si atom. In the second O site, O is bonded to three Ca and one Si atom to form OCa3Si tetrahedra that share corners with six equivalent FCa6 octahedra. The corner-sharing octahedra tilt angles range from 9–60°. In the third O site, O is bonded in a distorted rectangular see-saw-like geometry to three Ca and one Si atom. F is bonded to six Ca atoms to form FCa6 octahedra that share corners with six equivalent OCa3Si tetrahedra and faces with two equivalent FCa6 octahedra.

Ca₃SiO₄F为钛铁矿（Ilmenite）型衍生结构，结晶于正交晶系Pnma空间群。该晶体结构为三维网状结构。体系中存在两个不等价的钙（Ca）位点：在第一个钙位点中，钙原子以六配位几何构型与四个氧（O）原子和两个等价的氟（F）原子成键，Ca-O键长分布范围为2.35~2.54 Å，Ca-F键则分别具有一个较短键长（2.38 Å）与一个较长键长（2.65 Å）。在第二个钙位点中，钙原子同样以六配位几何构型与四个氧原子和两个等价的氟原子成键，其Ca-O键长分布范围为2.28~2.43 Å，对应的Ca-F键分别存在一个较短键长（2.48 Å）与一个较长键长（2.57 Å）。硅（Si）原子以四面体几何构型与四个氧原子成键，Si-O键中存在一个较短键长（1.67 Å）与三个较长键长（1.68 Å）。体系中存在三个不等价的氧位点：在第一个氧位点中，氧原子以畸变的矩形跷跷板状几何构型与三个钙原子和一个硅原子成键；在第二个氧位点中，氧原子与三个钙原子和一个硅原子成键，形成OCa₃Si四面体单元，该四面体与六个等价的FCa₆八面体共享顶点，这类顶点共享的八面体的倾斜角分布范围为9°~60°；在第三个氧位点中，氧原子同样以畸变的矩形跷跷板状几何构型与三个钙原子和一个硅原子成键。氟原子与六个钙原子成键，形成FCa₆八面体单元，该八面体与六个等价的OCa₃Si四面体共享顶点，并与两个等价的FCa₆八面体共享面。