2012/10/15 by Andreas Hermann, Alexandra McSorley, N. W. Ashcroft +1 · 1 citation
Materials Science · Physics and Astronomy · #Boron and Carbon Nanomaterials Research #Rare-earth and actinide compounds #Superconductivity in MgB2 and Alloys
paper · doi:10.1021/ja308492g
openalex publication_date 2012/10/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/16
Structural diversity and a variety of bonding schemes emerge as characteristics of the Li-B phase diagram in this ground-state theoretical investigation. We studied stoichiometries ranging from LiB(15) to Li(5)B, over a pressure range from 1 atm to 300 GPa. At P = 1 atm, stability is found for the experimentally known LiB(0.8-1.0), LiB(3), and Li(3)B(14) phases. As the pressure rises, the latter two structures are no longer even metastable, while the LiB(0.8-1.0) structures change in geometry and narrow their range of off-stoichiometry, eventually coming at high pressure to a diamondoid NaTl-type LiB. This phase then dominates the convex hull of stability. Other phases emerge as stable points at some pressure: LiB(4), Li(3)B(2), Li(2)B, and Li(5)B. At the boron-rich end, one obtains structures expectedly containing polyhedral motifs, and geometries are governed by Wade-Mingos electron counts; LiB(4) has a BaAl(4) structure. In the center and on the lithium-rich side of the phase diagram, Zintl-phase considerations, i.e., bonding between B(n-) entities, give us insight into the structures-tetrahedral B(-) networks in LiB; B pairs to isolated bonds in Li(5)B.