Evolutionary crystal structure prediction searches have been employed to explore the ternary Li-F-H system at 300 GPa. Metastable phases were uncovered within the static lattice approximation, with LiF3H2, LiF2H, Li3F4H, LiF4H4, Li2F3H and LiF3H lying within 50 meV/atom of the 0 K convex hull. All of these phases contain HnFn+1− (n = 1; 2) anions, and Li+ cations. Other structural motifs such as LiF slabs, H3+ molecules, and Fδ− ions are present in some of the low enthalpy Li-F-H structures. The bonding within the HnFn+1− molecules, which may be bent or linear, symmetric or asymmetric, is analyzed. The five phases closest to the hull are insulators, while LiF3H is metallic and predicted to have a vanishingly small superconducting critical temperature. This study lays the foundation for future investigations of the role of temperature and anharmonicity on the stability and properties of compounds and alloys in the Li-F-H ternary system.
@article{arxiv.2012.15336,
title = {The Li-F-H Ternary System at High Pressures},
author = {Tiange Bi and Andrew Shamp and Tyson Terpstra and Russell J. Hemley and Eva Zurek},
journal= {arXiv preprint arXiv:2012.15336},
year = {2021}
}