Materials Data on Ca3Sn2S7 by Materials Project

Ca3Sn2S7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ca–S bond distances ranging from 2.77–3.41 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Ca–S bond distances ranging from 2.78–3.37 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ca–S bond distances ranging from 2.79–3.04 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four S2- atoms to form corner-sharing SnS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.38–2.49 Å. In the second Sn4+ site, Sn4+ is bonded to four S2- atoms to form corner-sharing SnS4 tetrahedra. There are a spread of Sn–S bond distances ranging from 2.37–2.51 Å. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded to two Ca2+ and two Sn4+ atoms to form distorted corner-sharing SCa2Sn2 trigonal pyramids. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three Ca2+ and one Sn4+ atom. In the third S2- site, S2- is bonded in a distorted see-saw-like geometry to three Ca2+ and one Sn4+ atom. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to three Ca2+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded to three Ca2+ and one Sn4+ atom to form distorted SCa3Sn tetrahedra that share corners with three equivalent SCa2Sn2 trigonal pyramids and an edgeedge with one SCa3Sn tetrahedra. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to three Ca2+ and one Sn4+ atom. In the seventh S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two Ca2+ and one Sn4+ atom.

Ca₃Sn₂S₇结晶于单斜晶系P2₁/c空间群，其结构为三维结构。存在三个不等价的Ca²+位点：在第一个Ca²+位点中，Ca²+以六配位几何与六个S²-原子成键，Ca-S键长分布范围为2.77~3.41埃；在第二个Ca²+位点中，Ca²+以七配位几何与七个S²-原子成键，Ca-S键长分布范围为2.78~3.37埃；在第三个Ca²+位点中，Ca²+以六配位几何与六个S²-原子成键，Ca-S键长分布范围为2.79~3.04埃。存在两个不等价的Sn⁴+位点：在第一个Sn⁴+位点中，Sn⁴+与四个S²-原子成键，形成共顶点的SnS₄四面体，Sn-S键长分布范围为2.38~2.49埃；在第二个Sn⁴+位点中，Sn⁴+与四个S²-原子成键，形成共顶点的SnS₄四面体，Sn-S键长分布范围为2.37~2.51埃。存在七个不等价的S²-位点：在第一个S²-位点中，S²-与两个Ca²+和两个Sn⁴+原子成键，形成畸变的共顶点SCa₂Sn₂三角锥；在第二个S²-位点中，S²-以四配位几何与三个Ca²+和一个Sn⁴+原子成键；在第三个S²-位点中，S²-以畸变跷跷板型几何与三个Ca²+和一个Sn⁴+原子成键；在第四个S²-位点中，S²-以四配位几何与三个Ca²+和一个Sn⁴+原子成键；在第五个S²-位点中，S²-与三个Ca²+和一个Sn⁴+原子成键，形成畸变的SCa₃Sn四面体，该四面体与三个等价的SCa₂Sn₂三角锥共顶点，并与一个SCa₃Sn四面体共边；在第六个S²-位点中，S²-以畸变矩形跷跷板型几何与三个Ca²+和一个Sn⁴+原子成键；在第七个S²-位点中，S²-以畸变三角非共面几何与两个Ca²+和一个Sn⁴+原子成键。