Abstract
<title>Abstract</title> <p> In this article, we explore the Ba <sub>2</sub> HoXO <sub>6</sub> (X = Rh, Ru, and Os) double perovskite for its physical properties i.e. structural, electronical, optical, magnetic, and thermoelectric properties of theoretically investigated cubic compounds under PBE-GGA approximation by quantum-based density functional theory (DFT) within WIEN2K software. The structural, electronical, optical, magnetic, and thermoelectric properties of studied materials have been investigated for the energy renewable devices. Electronic properties of studied materials are explained by describing the band gap and density of states under study PBE-GGA approximation and the results abundantly evident that the studied material have indirect band gap and half metallic semiconductor. For optical behavior of studied materials, we analyzed complex dielectric functions, optical conductivity σ(ω), Absorbance α(ω), Reflectivity R(ω), and Loss parameter L(ω). Also, we analyze the thermal behavior of studied materials by calculating charge carrier concentration (n), electrical conductivity σ/τ, Seebeck coefficient (S), thermal conductivity K/τ, specific heat capacity C <sub>v</sub> , magnetic susceptibility χ, and power factor theoretically which predict the materials are eco-friendly and could be used in energy renewable devices. These properties are calculated by Boltz-Trap code under Wien2K code. All these properties are studied though first-Principle calculation and leads to new renewable devices. </p>