Finite Temperature and Pressure Properties of Os₂B₃ from First-Principles Simulation

Transition metal boride Os₂B₃ has excellent incompressibility and thermal stability for potential applications in extreme high-pressure high-temperature environments. In this study, we use density functional theory (DFT) to simulate the electronic and mechanical properties of Os₂B₃. We also perform phonon calculations with the quasiharmonic approximation (QHA) to study finite-temperature and finite-pressure thermodynamic quantities of Os₂B₃, including its P-V-T curves, phonon spectra, bulk modulus, specific heat, thermal expansion, and the Grüneisen parameter. The comparison of our simulation to experimental P-V-T data underscores the utility of the Armiento-Mattsson 2005 (AM05) DFT functional and QHA for describing thermodynamic properties of solid-state systems.