Materials Data on BaCeI4 by Materials Project

BaCeI4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Ba is bonded in a 8-coordinate geometry to eight I atoms. There are a spread of Ba–I bond distances ranging from 3.54–3.64 Å. Ce is bonded in a 8-coordinate geometry to eight I atoms. There are a spread of Ce–I bond distances ranging from 3.34–3.41 Å. There are four inequivalent I sites. In the first I site, I is bonded in a distorted see-saw-like geometry to two equivalent Ba and two equivalent Ce atoms. In the second I site, I is bonded in a distorted see-saw-like geometry to two equivalent Ba and two equivalent Ce atoms. In the third I site, I is bonded to two equivalent Ba and two equivalent Ce atoms to form a mixture of distorted edge and corner-sharing IBa2Ce2 tetrahedra. In the fourth I site, I is bonded to two equivalent Ba and two equivalent Ce atoms to form a mixture of distorted edge and corner-sharing IBa2Ce2 trigonal pyramids.

BaCeI₄结晶于三斜晶系P-1空间群，其晶体结构为三维结构。Ba原子以八配位构型与8个I原子成键，Ba-I键的键长分布范围为3.54~3.64 Å。Ce原子同样以八配位构型与8个I原子成键，Ce-I键的键长分布范围为3.34~3.41 Å。体系中存在4种不等价的I原子占位：在第一种I原子占位中，I原子以畸变跷跷板型配位构型与2个等价的Ba原子和2个等价的Ce原子成键；在第二种I原子占位中，I原子以畸变跷跷板型配位构型与2个等价的Ba原子和2个等价的Ce原子成键；在第三种I原子占位中，I原子与2个等价的Ba原子和2个等价的Ce原子成键，形成兼具畸变边共享与角共享的IBa₂Ce₂四面体结构单元；在第四种I原子占位中，I原子与2个等价的Ba原子和2个等价的Ce原子成键，形成兼具畸变边共享与角共享的IBa₂Ce₂三角锥结构单元。