Materials Data on La3AlCrS7 by Materials Project

La3CrAlS7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. La3+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.88–3.47 Å. Cr2+ is bonded to six equivalent S2- atoms to form face-sharing CrS6 octahedra. There are three shorter (2.54 Å) and three longer (2.55 Å) Cr–S bond lengths. Al3+ is bonded in a tetrahedral geometry to four S2- atoms. There are one shorter (2.23 Å) and three longer (2.26 Å) Al–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted tetrahedral geometry to three equivalent La3+ and one Al3+ atom. In the second S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent La3+ and one Al3+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to four equivalent La3+ and two equivalent Cr2+ atoms.

La₃CrAlS₇结晶于六方晶系P6₃空间群，其结构为三维框架。La³+以7配位构型与8个S²-阴离子成键，La-S键长分布范围为2.88~3.47埃。Cr²+与6个等价的S²-阴离子结合，形成面共享的CrS₆八面体，其中存在3条较短的Cr-S键（键长2.54埃）与3条较长的Cr-S键（键长2.55埃）。Al³+以四面体构型与4个S²-阴离子成键，Al-S键长包含1条较短键（2.23埃）与3条较长键（2.26埃）。该晶体存在3种不等价的S²-占位位点：第一种S²-位点中，S²-以畸变四面体构型与3个等价的La³+及1个Al³+结合；第二种S²-位点中，S²-以畸变矩形跷跷板型构型与3个等价的La³+及1个Al³+结合；第三种S²-位点中，S²-以5配位构型与4个等价的La³+及2个等价的Cr²+结合。