Materials Data on Si3N4 by Materials Project

Si3N4 is Hausmannite-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four N3- atoms to form a mixture of corner and edge-sharing SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 62–66°. There are a spread of Si–N bond distances ranging from 1.71–1.77 Å. In the second Si4+ site, Si4+ is bonded to six N3- atoms to form SiN6 octahedra that share corners with eight SiN6 octahedra, corners with four equivalent SiN4 tetrahedra, edges with two equivalent SiN6 octahedra, and an edgeedge with one SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Si–N bond distances ranging from 1.87–2.12 Å. In the third Si4+ site, Si4+ is bonded to six N3- atoms to form SiN6 octahedra that share corners with four equivalent SiN6 octahedra, corners with two equivalent SiN4 tetrahedra, edges with four SiN6 octahedra, and edges with two equivalent SiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Si–N bond distances ranging from 1.85–1.95 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to four Si4+ atoms to form corner-sharing NSi4 tetrahedra. In the second N3- site, N3- is bonded in a rectangular see-saw-like geometry to four Si4+ atoms. In the third N3- site, N3- is bonded in a rectangular see-saw-like geometry to four Si4+ atoms.

氮化硅（Si₃N₄）具有类黑锰矿（Hausmannite）结构，结晶于正交晶系Pnma空间群。该结构为三维骨架结构。存在三个不等价的四价硅离子（Si⁴⁺）位点。
在第一个四价硅离子位点中，四价硅离子与四个三价氮离子（N³⁻）配位，形成兼具共角与共边连接的SiN₄四面体。共角八面体的倾斜角范围为62°~66°，Si-N键长分布在1.71~1.77 Å之间。
在第二个四价硅离子位点中，四价硅离子与六个三价氮离子配位，形成SiN₆八面体；该八面体分别与八个SiN₆八面体共角、四个等价的SiN₄四面体共角、两个等价的SiN₆八面体共边，以及一个SiN₄四面体共边。其共角八面体倾斜角范围为49°~54°，Si-N键长分布在1.87~2.12 Å之间。
在第三个四价硅离子位点中，四价硅离子与六个三价氮离子配位，形成SiN₆八面体；该八面体分别与四个等价的SiN₆八面体共角、两个等价的SiN₄四面体共角、四个SiN₆八面体共边，以及两个等价的SiN₄四面体共边。其共角八面体倾斜角范围为50°~54°，Si-N键长分布在1.85~1.95 Å之间。
存在三个不等价的三价氮离子（N³⁻）位点。
在第一个三价氮离子位点中，三价氮离子与四个四价硅离子配位，形成共角连接的NSi₄四面体。
在第二个三价氮离子位点中，三价氮离子以矩形跷板式配位构型与四个四价硅离子结合。
在第三个三价氮离子位点中，三价氮离子同样以矩形跷板式配位构型与四个四价硅离子结合。

搜集汇总

背景与挑战

背景概述

该数据集详细描述了氮化硅（Si3N4）的晶体结构，包括其类黑锰矿正交晶系（Pnma空间群）特征，以及三种不等价Si4+和N3-位点的键合构型、键长范围和几何共享关系。数据重点提供了原子尺度的结构信息，如SiN4四面体和SiN6八面体的形成与连接方式，适用于材料科学和晶体学研究。