Crystal structures and stability of LiCeF5 and LiThF5 at high pressures: A comparative study of the coordination around the Ce4+ and Th4+ ions

Normalized lattice parameters and unit-cell volumes of LiCeF5 (black symbols) and LiThF5 (red symbols) as a function of pressure. The open circles and full squares stand for the normalized c and a parameters, respectively. The diamonds represent the normalized unit-cell volumes. The solid lines are the fits of the Birch-Murnaghan equation of state to the bulk compressibility data.