First-principles predictions of electrical and thermal conductivity of platinum and iridium at high pressure conditions*

Platinum-group metals, such as iridium (Ir) are important elements for their unique high density, high melting temperature, and high corrosion resistance. Platinum (Pt) has a high stability solid-phase over a range of pressure and temperature and is often used as a pressure standard. We investigate the fundamental properties, thermal and electrical conductivities of Ir and Pt at high pressure and temperature conditions using the first-principles methods. We compare experimental data with results from two theoretical approaches in the framework of Kubo-Greenwood theory. The scattering mechanism is simulated by (1) coherent potential approximation via Debye model, and (2) first-principles molecular dynamics. The study provides electrical and thermal conductivity at high (P, T) conditions and discusses the violation of the Wiedemann-Franz law.