Discovery of new 1D electrides by coupling materials database searches and first-principles analysis

An electride is a unique type of ionic compound in which electrons distributed in structural cavities behave as anions. The availability of the large cavity space with metallic electrons makes the new electrides very interesting for many technical applications. However, only a couple of them have been experimentally synthesized and theoretically reported. We discover new class of electrides based on 1D building blocks by coupling materials database searches and first-principles-calculations-based analysis. This new class of electrides, composed of 1D nanorod building blocks, has crystal structures that mimic β-TiCl₃ with the position of anions and cations exchanged. Unlike the weakly coupled nanorods of β-TiCl₃, Cs₃O and Ba₃N retain 1D anionic electrons along the hollow inter-rod sites; additionally, strong inter-rod interaction in C₃O and Ba₃N induces band inversion in a 2D superatomic triangular lattice, resulting in Dirac nodal lines [1]. Our work [1] represents an important scientific advancement over previous knowledge of realizing electrides.

[1] New electrides based on one-dimensional building blocks, Changwon Park, Sung Wng Kim, Mina Yoon, Phys. Rev. Lett., accepted (2017).