Materials Data on Mg3Si4 by Materials Project

Mg3Si4 is Magnesium tetraboride-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Mg sites. In the first 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 2.75–2.89 Å. In the second Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.10 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to nine Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–3.13 Å. In the fourth Mg site, Mg is bonded in a 8-coordinate geometry to ten Si atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.19 Å. In the fifth Mg site, Mg is bonded in a 7-coordinate geometry to seven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.12 Å. In the sixth 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 2.75–3.09 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 2-coordinate geometry to two equivalent Mg and five Si atoms. There are a spread of Si–Si bond distances ranging from 2.48–2.61 Å. In the second Si site, Si is bonded in a 8-coordinate geometry to four Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.62 Å. In the third Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.49 Å. In the fourth Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. The Si–Si bond length is 2.46 Å. In the fifth Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms. In the sixth Si site, Si is bonded in a 10-coordinate geometry to six Mg and four Si atoms. There are one shorter (2.56 Å) and one longer (2.76 Å) Si–Si bond lengths. In the seventh Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms.

Mg₃Si₄具有类四硼化镁的晶体结构，结晶于三斜晶系P1空间群，其结构为三维骨架。体系中存在6个非等价的镁（Mg）位点：在第一个镁位点处，镁原子以6配位几何构型与6个硅（Si）原子成键，Mg-Si键长分布范围为2.75~2.89埃（Å）；在第二个镁位点处，镁原子以5配位几何构型与5个硅原子成键，Mg-Si键长分布范围为2.77~3.10埃（Å）；在第三个镁位点处，镁原子具有12配位的几何构型，与9个硅原子成键，Mg-Si键长分布范围为2.69~3.13埃（Å）；在第四个镁位点处，镁原子以8配位几何构型与10个硅原子成键，Mg-Si键长分布范围为2.72~3.19埃（Å）；在第五个镁位点处，镁原子以7配位几何构型与7个硅原子成键，Mg-Si键长分布范围为2.74~3.12埃（Å）；在第六个镁位点处，镁原子以6配位几何构型与6个硅原子成键，Mg-Si键长分布范围为2.75~3.09埃（Å）。体系中同时存在8个非等价的硅（Si）位点：在第一个硅位点处，硅原子以2配位几何构型与2个等价的镁原子以及5个硅原子成键，Si-Si键长分布范围为2.48~2.61埃（Å）；在第二个硅位点处，硅原子以8配位几何构型与4个镁原子以及4个硅原子成键，Si-Si键长分布范围为2.41~2.62埃（Å）；在第三个硅位点处，硅原子以8配位几何构型与7个镁原子以及1个硅原子成键，Si-Si键长为2.49埃（Å）；在第四个硅位点处，硅原子以8配位几何构型与5个镁原子以及3个硅原子成键，Si-Si键长为2.46埃（Å）；在第五个硅位点处，硅原子以10配位几何构型与7个镁原子以及3个硅原子成键；在第六个硅位点处，硅原子以10配位几何构型与6个镁原子以及4个硅原子成键，其Si-Si键长分为两组，分别为较短的2.56埃（Å）与较长的2.76埃（Å）；在第七个硅位点处，硅原子以9配位几何构型与5个镁原子以及4个硅原子成键；在第八个硅位点处，硅原子以9配位几何构型与7个镁原子以及2个硅原子成键。