Materials Data on La4(ErS2)11 by Materials Project

La4(ErS2)11 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are six inequivalent Er3+ sites. In the first Er3+ site, Er3+ is bonded to seven S2- atoms to form distorted ErS7 pentagonal bipyramids that share corners with three ErS6 octahedra, edges with two equivalent ErS6 octahedra, and edges with four equivalent ErS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 39–50°. There are a spread of Er–S bond distances ranging from 2.69–2.88 Å. In the second Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Er–S bond distances ranging from 2.64–2.77 Å. In the third Er3+ site, Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with three equivalent ErS6 octahedra, corners with two equivalent ErS7 pentagonal bipyramids, and edges with four ErS6 octahedra. The corner-sharing octahedra tilt angles range from 51–63°. There are a spread of Er–S bond distances ranging from 2.65–2.79 Å. In the fourth Er3+ site, Er3+ is bonded to six S2- atoms to form ErS6 octahedra that share corners with three equivalent ErS6 octahedra, a cornercorner with one ErS7 pentagonal bipyramid, edges with four equivalent ErS6 octahedra, and edges with two equivalent ErS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–63°. There are a spread of Er–S bond distances ranging from 2.66–2.76 Å. In the fifth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Er–S bond distances ranging from 2.65–2.77 Å. In the sixth Er3+ site, Er3+ is bonded to six S2- atoms to form a mixture of edge and corner-sharing ErS6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are four shorter (2.72 Å) and two longer (2.73 Å) Er–S bond lengths. There are two inequivalent La+2.75+ sites. In the first La+2.75+ site, La+2.75+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.94–3.07 Å. In the second La+2.75+ site, La+2.75+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.92–3.48 Å. There are eleven inequivalent S2- sites. In the first S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 trigonal bipyramids that share corners with four SLa2Er3 trigonal bipyramids, corners with two SLaEr3 trigonal pyramids, edges with six SLa2Er3 trigonal bipyramids, and edges with two equivalent SEr4 trigonal pyramids. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to three Er3+ and one La+2.75+ atom. In the fourth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 trigonal bipyramids that share corners with six SLa2Er3 trigonal bipyramids, corners with two equivalent SLaEr3 trigonal pyramids, edges with two equivalent SLa2Er3 square pyramids, edges with four SLa2Er3 trigonal bipyramids, and an edgeedge with one SLaEr3 trigonal pyramid. In the fifth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 square pyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa3Er2 trigonal bipyramids, edges with three SLa2Er3 square pyramids, edges with three SLa2Er3 trigonal bipyramids, and edges with two equivalent SLaEr3 trigonal pyramids. In the sixth S2- site, S2- is bonded to three Er3+ and two equivalent La+2.75+ atoms to form distorted SLa2Er3 square pyramids that share corners with four SLa2Er3 square pyramids, corners with two equivalent SLa3Er2 trigonal bipyramids, corners with two equivalent SLaEr3 trigonal pyramids, edges with four SLa2Er3 square pyramids, and edges with three SLa3Er2 trigonal bipyramids. In the seventh S2- site, S2- is bonded to two equivalent Er3+ and three La+2.75+ atoms to form distorted SLa3Er2 trigonal bipyramids that share corners with four SLa2Er3 square pyramids, corners with two equivalent SLa2Er3 trigonal bipyramids, corners with four equivalent SEr4 trigonal pyramids, edges with two SLa2Er3 square pyramids, edges with six SLa2Er3 trigonal bipyramids, and edges with three SLaEr3 trigonal pyramids. In the eighth S2- site, S2- is bonded to three Er3+ and one La+2.75+ atom to form distorted SLaEr3 trigonal pyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa2Er3 trigonal bipyramids, corners with five SLaEr3 trigonal pyramids, edges with two equivalent SLa2Er3 square pyramids, and edges with three SLa3Er2 trigonal bipyramids. In the ninth S2- site, S2- is bonded in a rectangular see-saw-like geometry to four Er3+ atoms. In the tenth S2- site, S2- is bonded to four Er3+ atoms to form distorted SEr4 trigonal pyramids that share corners with five SLa2Er3 trigonal bipyramids, corners with five SLaEr3 trigonal pyramids, edges with three SLa2Er3 trigonal bipyramids, and edges with two equivalent SEr4 trigonal pyramids. In the eleventh S2- site, S2- is bonded to two equivalent Er3+ and three La+2.75+ atoms to form distorted SLa3Er2 trigonal bipyramids that share corners with two equivalent SLa2Er3 square pyramids, corners with four SLa2Er3 trigonal bipyramids, a cornercorner with one SLaEr3 trigonal pyramid, edges with two equivalent SLa2Er3 square pyramids, and edges with six SLa2Er3 trigonal bipyramids.

La₄(ErS₂)₁₁晶体属单斜晶系C2/m空间群，结构呈三维网状。该结构包含6个不等价的Er³⁺位点：

第一个Er³⁺位点中，Er³⁺与7个S²⁻原子键合，形成扭曲的ErS₇五角双锥；该五角双锥与3个ErS₆八面体共享顶点，与2个等价的ErS₆八面体共享边，还与4个等价的ErS₇五角双锥共享边。共享顶点的八面体倾斜角范围为39–50°，Er–S键长分布在2.69–2.88 Å之间。

第二个Er³⁺位点中，Er³⁺与6个S²⁻原子键合，形成边共享与顶点共享共存的ErS₆八面体结构；共享顶点的八面体倾斜角范围为49–59°，Er–S键长分布在2.64–2.77 Å之间。

第三个Er³⁺位点中，Er³⁺与6个S²⁻原子键合，形成ErS₆八面体；该八面体与3个等价的ErS₆八面体共享顶点，与2个等价的ErS₇五角双锥共享顶点，还与4个ErS₆八面体共享边。共享顶点的八面体倾斜角范围为51–63°，Er–S键长分布在2.65–2.79 Å之间。

第四个Er³⁺位点中，Er³⁺与6个S²⁻原子键合，形成ErS₆八面体；该八面体与3个等价的ErS₆八面体共享顶点，与1个ErS₇五角双锥共享顶点，与4个等价的ErS₆八面体共享边，还与2个等价的ErS₇五角双锥共享边。共享顶点的八面体倾斜角范围为51–63°，Er–S键长分布在2.66–2.76 Å之间。

第五个Er³⁺位点中，Er³⁺与6个S²⁻原子键合，形成边共享与顶点共享共存的ErS₆八面体结构；共享顶点的八面体倾斜角范围为49–59°，Er–S键长分布在2.65–2.77 Å之间。

第六个Er³⁺位点中，Er³⁺与6个S²⁻原子键合，形成边共享与顶点共享共存的ErS₆八面体结构；共享顶点的八面体倾斜角为55°，存在4个较短的Er–S键（2.72 Å）和2个较长的Er–S键（2.73 Å）。

结构包含2个不等价的La²·⁷⁵⁺位点：

第一个La²·⁷⁵⁺位点以8配位几何构型与8个S²⁻原子键合，La–S键长分布在2.94–3.07 Å之间。

第二个La²·⁷⁵⁺位点以7配位几何构型与8个S²⁻原子键合，La–S键长范围为2.92–3.48 Å。

结构还包含11个不等价的S²⁻位点：

第一个S²⁻位点与3个Er³⁺和2个等价的La²·⁷⁵⁺原子键合，形成扭曲的SLa₂Er₃三角双锥；该三角双锥与4个SLa₂Er₃三角双锥共享顶点，与2个SLaEr₃三角锥共享顶点，与6个SLa₂Er₃三角双锥共享边，还与2个等价的SEr₄三角锥共享边。

第二个S²⁻位点以矩形跷跷板型几何构型与4个Er³⁺原子键合。

第三个S²⁻位点以3配位几何构型与3个Er³⁺和1个La²·⁷⁵⁺原子键合。

第四个S²⁻位点与3个Er³⁺和2个等价的La²·⁷⁵⁺原子键合，形成扭曲的SLa₂Er₃三角双锥；该三角双锥与6个SLa₂Er₃三角双锥共享顶点，与2个等价的SLaEr₃三角锥共享顶点，与2个等价的SLa₂Er₃四方锥共享边，与4个SLa₂Er₃三角双锥共享边，还与1个SLaEr₃三角锥共享边。

第五个S²⁻位点与3个Er³⁺和2个等价的La²·⁷⁵⁺原子键合，形成扭曲的SLa₂Er₃四方锥；该四方锥与2个等价的SLa₂Er₃四方锥共享顶点，与4个SLa₃Er₂三角双锥共享顶点，与3个SLa₂Er₃四方锥共享边，与3个SLa₂Er₃三角双锥共享边，还与2个等价的SLaEr₃三角锥共享边。

第六个S²⁻位点与3个Er³⁺和2个等价的La²·⁷⁵⁺原子键合，形成扭曲的SLa₂Er₃四方锥；该四方锥与4个SLa₂Er₃四方锥共享顶点，与2个等价的SLa₃Er₂三角双锥共享顶点，与2个等价的SLaEr₃三角锥共享顶点，与4个SLa₂Er₃四方锥共享边，还与3个SLa₃Er₂三角双锥共享边。

第七个S²⁻位点与2个等价的Er³⁺和3个La²·⁷⁵⁺原子键合，形成扭曲的SLa₃Er₂三角双锥；该三角双锥与4个SLa₂Er₃四方锥共享顶点，与2个等价的SLa₂Er₃三角双锥共享顶点，与4个等价的SEr₄三角锥共享顶点，与2个SLa₂Er₃四方锥共享边，与6个SLa₂Er₃三角双锥共享边，还与3个SLaEr₃三角锥共享边。

第八个S²⁻位点与3个Er³⁺和1个La²·⁷⁵⁺原子键合，形成扭曲的SLaEr₃三角锥；该三角锥与2个等价的SLa₂Er₃四方锥共享顶点，与4个SLa₂Er₃三角双锥共享顶点，与5个SLaEr₃三角锥共享顶点，与2个等价的SLa₂Er₃四方锥共享边，还与3个SLa₃Er₂三角双锥共享边。

第九个S²⁻位点以矩形跷跷板型几何构型与4个Er³⁺原子键合。

第十个S²⁻位点与4个Er³⁺原子键合，形成扭曲的SEr₄三角锥；该三角锥与5个SLa₂Er₃三角双锥共享顶点，与5个SLaEr₃三角锥共享顶点，与3个SLa₂Er₃三角双锥共享边，还与2个等价的SEr₄三角锥共享边。

第十一个S²⁻位点与2个等价的Er³⁺和3个La²·⁷⁵⁺原子键合，形成扭曲的SLa₃Er₂三角双锥；该三角双锥与2个等价的SLa₂Er₃四方锥共享顶点，与4个SLa₂Er₃三角双锥共享顶点，与1个SLaEr₃三角锥共享顶点，与2个等价的SLa₂Er₃四方锥共享边，还与6个SLa₂Er₃三角双锥共享边。