Influence of pressure on the different properties of LiXO 3 (X = Si, Pr) perovskites: DFT investigated

Abstract We probe how pressure tunes the structural, mechanical, electronic, optical, and thermodynamic properties of lithium-based perovskites LiXO 3 (X = Si, Pr). Under compression, both materials retain their cubic structure, but their physical properties diverge dramatically. LiSiO 3 becomes stronger and more ductile, its metallic character and melting point maintained under pressure —a signature of a robust, covalently bonded network with band overlap. Its thermal transport, however, shows a high-pressure softening of lattice vibrations. In contrast, LiPrO 3 responds erratically; with its softer lattice, narrow gap, and anomalous thermal properties fluctuates under stress, which reveals the profound influence of Pr 4 f electrons. These distinct behaviors, including LiPrO 3 ’s unstable Debye temperature and non-monotonic melting point, signal different technological futures: LiSiO 3 for high-stress optics and protective coatings, LiPrO 3 for smart sensors and pressure-switchable electronics. This study maps a course for tailoring perovskite materials by design, linking chemistry to performance under extreme conditions.