Materials Data on CeThSi4 by Materials Project

ThCeSi4 is hexagonal omega structure-derived structured and crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Th4+ is bonded to twelve Si2- atoms to form ThSi12 cuboctahedra that share edges with four equivalent ThSi12 cuboctahedra, edges with eight equivalent CeSi12 cuboctahedra, faces with four equivalent ThSi12 cuboctahedra, and faces with four equivalent CeSi12 cuboctahedra. There are four shorter (3.14 Å) and eight longer (3.15 Å) Th–Si bond lengths. Ce4+ is bonded to twelve Si2- atoms to form CeSi12 cuboctahedra that share edges with four equivalent CeSi12 cuboctahedra, edges with eight equivalent ThSi12 cuboctahedra, faces with four equivalent ThSi12 cuboctahedra, and faces with four equivalent CeSi12 cuboctahedra. There are four shorter (3.13 Å) and eight longer (3.14 Å) Ce–Si bond lengths. There are three inequivalent Si2- sites. In the first Si2- site, Si2- is bonded in a 9-coordinate geometry to two equivalent Th4+, four equivalent Ce4+, and three Si2- atoms. There are one shorter (2.35 Å) and two longer (2.37 Å) Si–Si bond lengths. In the second Si2- site, Si2- is bonded in a 9-coordinate geometry to four equivalent Th4+, two equivalent Ce4+, and three Si2- atoms. The Si–Si bond length is 2.39 Å. In the third Si2- site, Si2- is bonded in a 9-coordinate geometry to four equivalent Th4+, two equivalent Ce4+, and three Si2- atoms. All Si–Th bond lengths are 3.15 Å. There are two shorter (2.37 Å) and one longer (2.39 Å) Si–Si bond lengths.

ThCeSi₄为六方ω结构衍生晶体，属四方晶系I-4m2空间群，其晶体结构为三维框架。四价钍离子（Th⁴+）与12个二价硅离子（Si²-）配位，形成ThSi₁₂立方八面体（cuboctahedra）配位多面体；该多面体分别与4个等价的ThSi₁₂立方八面体共享棱、与8个等价的CeSi₁₂立方八面体共享棱，同时与4个等价的ThSi₁₂立方八面体共享面、与4个等价的CeSi₁₂立方八面体共享面。Th-Si键长分为两组：4条较短键长（3.14 Å）与8条较长键长（3.15 Å）。

四价铈离子（Ce⁴+）与12个Si²-配位，形成CeSi₁₂立方八面体配位多面体；该多面体分别与4个等价的CeSi₁₂立方八面体共享棱、与8个等价的ThSi₁₂立方八面体共享棱，同时与4个等价的ThSi₁₂立方八面体共享面、与4个等价的CeSi₁₂立方八面体共享面。Ce-Si键长同样分为两组：4条较短键长（3.13 Å）与8条较长键长（3.14 Å）。

该晶体结构中存在3种不等价的Si²-占位位点。在第一种Si²-位点中，Si²-为9配位构型，分别与2个等价的Th⁴+、4个等价的Ce⁴+以及3个Si²-原子配位；Si-Si键长包含1条较短键（2.35 Å）与2条较长键（2.37 Å）。在第二种Si²-位点中，Si²-为9配位构型，分别与4个等价的Th⁴+、2个等价的Ce⁴+以及3个Si²-原子配位，Si-Si键长为2.39 Å。在第三种Si²-位点中，Si²-为9配位构型，分别与4个等价的Th⁴+、2个等价的Ce⁴+以及3个Si²-原子配位，所有Th-Si键长均为3.15 Å；该位点的Si-Si键长包含2条较短键（2.37 Å）与1条较长键（2.39 Å）。