Materials Data on MgSi2 by Materials Project

MgSi2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.18 Å. In the second Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–2.93 Å. In the third Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.82–3.02 Å. In the fourth Mg site, Mg is bonded in a 5-coordinate geometry to seven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–3.18 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.38–2.44 Å. In the second Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. There are two shorter (2.39 Å) and one longer (2.40 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 6-coordinate geometry to two equivalent Mg and four Si atoms. There are two shorter (2.34 Å) and one longer (2.60 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a distorted hexagonal planar geometry to two equivalent Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.34–2.54 Å. In the fifth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two equivalent Si atoms. In the sixth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two equivalent Si atoms. In the seventh Si site, Si is bonded in a 6-coordinate geometry to two Mg and four Si atoms. The Si–Si bond length is 2.42 Å. In the eighth Si site, Si is bonded in a 6-coordinate geometry to two Mg and four Si atoms.

二硅化镁（MgSi₂）结晶于三斜晶系P1空间群，其结构为三维结构。体系内存在4个不等价的镁位点：在第一个镁位点中，镁原子以4配位几何与5个硅原子成键，镁-硅键键长分布范围为2.74~3.18 Å；在第二个镁位点中，镁原子以6配位几何与6个硅原子成键，镁-硅键键长分布范围为2.80~2.93 Å；在第三个镁位点中，镁原子以8配位几何与8个硅原子成键，镁-硅键键长分布范围为2.82~3.02 Å；在第四个镁位点中，镁原子以5配位几何与7个硅原子成键，镁-硅键键长分布范围为2.76~3.18 Å。体系内同时存在8个不等价的硅位点：在第一个硅位点中，硅原子以7配位几何与4个镁原子及3个硅原子成键，硅-硅键键长分布范围为2.38~2.44 Å；在第二个硅位点中，硅原子以7配位几何与4个镁原子及3个硅原子成键，其中存在2条较短的硅-硅键（键长2.39 Å）与1条较长的硅-硅键（键长2.40 Å）；在第三个硅位点中，硅原子以6配位几何与2个等价的镁原子及4个硅原子成键，其中存在2条较短的硅-硅键（键长2.34 Å）与1条较长的硅-硅键（键长2.60 Å）；在第四个硅位点中，硅原子以畸变六方平面配位几何与2个等价的镁原子及4个硅原子成键，硅-硅键键长分布范围为2.34~2.54 Å；在第五个硅位点中，硅原子以7配位几何与5个镁原子及2个等价的硅原子成键；在第六个硅位点中，硅原子以7配位几何与5个镁原子及2个等价的硅原子成键；在第七个硅位点中，硅原子以6配位几何与2个镁原子及4个硅原子成键，硅-硅键键长为2.42 Å；在第八个硅位点中，硅原子以6配位几何与2个镁原子及4个硅原子成键。