Crystal and electronic structure of the ternary Zintl bismuthide BaLiBi

• Published in: Zeitschrift für anorganische und allgemeine Chemie (1950) 2023-10, Vol.649 (19)
• Main Authors: Ovchinnikov, Alexander, Bobev, Svilen
• Format: Article
• Language: English
• Subjects: Crystal structure; Electronic structure; Electrons; Ground state; Mathematical analysis; Relativistic effects; Unit cell
• ISSN: 0044-2313; 1521-3749
• DOI: 10.1002/zaac.202300128

Reported is the accurate refinement of the structure of the ternary bismuthide BaLiBi, based on single‐crystal X‐ray diffraction data. This compound crystallizes with the ZrBeSi structure type with the space group P 6 3 / mmc (no. 194), a =4.9917(6) Å, c =9.079(2) Å, V =195.92(7) Å 3 with two formula units per unit cell. In addition to being a colored ternary variant of the AlB 2 type, the crystal structure of BaLiBi can be also viewed as a “stuffed” variant of the NiAs structure, where the Bi atoms form a hexagonal close packing, the Ba atoms occupy the octahedral voids in this packing, and the Li atoms are located between adjacent tetrahedral voids on their common triangular faces. In the absence of direct Bi–Bi interactions, the BaLiBi crystal structure rationalized according to the notation (Ba 2+ )(Li + )(Bi 3− ), suggesting an electron‐balanced composition, i. e., a Zintl phase. In line with this notation, scalar‐relativistic first‐principle calculations with the LMTO code reveal a semiconducting ground state, with a bandgap of about 0.6 eV. Fully relativistic electronic structure calculations predict a semimetallic ground state.