Materials Data on Mg(ScSe2)2 by Materials Project

Mg(ScSe2)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded in a rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Mg–Se bond distances ranging from 2.56–2.66 Å. There are two inequivalent Sc3+ sites. In the first Sc3+ site, Sc3+ is bonded to five Se2- atoms to form ScSe5 trigonal bipyramids that share corners with four equivalent ScSe6 pentagonal pyramids, corners with two equivalent ScSe5 trigonal bipyramids, and a faceface with one ScSe6 pentagonal pyramid. There are a spread of Sc–Se bond distances ranging from 2.55–2.73 Å. In the second Sc3+ site, Sc3+ is bonded to six Se2- atoms to form distorted ScSe6 pentagonal pyramids that share corners with four equivalent ScSe5 trigonal bipyramids, edges with two equivalent ScSe6 pentagonal pyramids, and a faceface with one ScSe5 trigonal bipyramid. There are a spread of Sc–Se bond distances ranging from 2.64–2.86 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to one Mg2+ and three Sc3+ atoms. In the second Se2- site, Se2- is bonded in a distorted T-shaped geometry to one Mg2+ and two Sc3+ atoms. In the third Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Sc3+ atoms.Mg(ScSe₂)₂结晶于正交晶系（orthorhombic）Pnma空间群。该晶体结构为三维骨架结构。Mg²+以矩形跷跷板型配位几何与4个Se²-成键，Mg–Se键长分布范围为2.56~2.66 Å。体系中存在两个不等价的Sc³+配位位点。在第一个Sc³+位点中，Sc³+与5个Se²-成键形成ScSe₅三角双锥（trigonal bipyramid）结构，该结构分别与4个等价的ScSe₆五角锥（pentagonal pyramid）共享顶点、与2个等价的ScSe₅三角双锥共享顶点，并与1个ScSe₆五角锥共面。此位点的Sc–Se键长分布范围为2.55~2.73 Å。在第二个Sc³+位点中，Sc³+与6个Se²-成键形成畸变型ScSe₆五角锥结构，该结构分别与4个等价的ScSe₅三角双锥共享顶点、与2个等价的ScSe₆五角锥共享边，并与1个ScSe₅三角双锥共面。此位点的Sc–Se键长分布范围为2.64~2.86 Å。体系中存在三个不等价的Se²-配位位点。在第一个Se²-位点中，Se²-以四配位几何与1个Mg²+和3个Sc³+成键。在第二个Se²-位点中，Se²-以畸变T型配位几何与1个Mg²+和2个Sc³+成键。在第三个Se²-位点中，Se²-以矩形跷跷板型配位几何与1个Mg²+和3个Sc³+成键。