Materials Data on BaAg2SnSe4 by Materials Project

BaAg2SnSe4 crystallizes in the orthorhombic I222 space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight equivalent Se2- atoms. There are four shorter (3.48 Å) and four longer (3.50 Å) Ba–Se bond lengths. Ag1+ is bonded in a distorted see-saw-like geometry to four equivalent Se2- atoms. There are two shorter (2.59 Å) and two longer (2.99 Å) Ag–Se bond lengths. Sn4+ is bonded in a tetrahedral geometry to four equivalent Se2- atoms. All Sn–Se bond lengths are 2.58 Å. Se2- is bonded to two equivalent Ba2+, two equivalent Ag1+, and one Sn4+ atom to form a mixture of distorted corner and edge-sharing SeBa2Ag2Sn trigonal bipyramids.

BaAg₂SnSe₄结晶于正交晶系（orthorhombic）的I222空间群（space group），其结构为三维框架。Ba²+采取八配位几何构型（8-coordinate geometry），与8个等价的Se²-成键，Ba-Se键长分为两组：4个较短键长为3.48 Å，4个较长键长为3.50 Å。Ag⁺采取畸变跷跷板型几何构型（distorted see-saw-like geometry），与4个等价的Se²-成键，Ag-Se键长同样分为两组：2个较短键长为2.59 Å，2个较长键长为2.99 Å。Sn⁴+采取四面体几何构型（tetrahedral geometry），与4个等价的Se²-成键，所有Sn-Se键长均为2.58 Å。Se²-分别与2个等价的Ba²+、2个等价的Ag⁺以及1个Sn⁴+原子成键，形成兼具畸变角顶共享与边共享特征的SeBa₂Ag₂Sn三角双锥（trigonal bipyramids）结构单元。