Abstract
Based on first principles, we use GGA and PAW method in the framework of density functional theory to investigate electronic structure of perovskite ruthenate CaRuO3. Additionally, we also perform GGA+U calculation to include the on site Coulomb interaction of Ru ion. The total-energy studies show that CaRuO3 stabilize in metallic conducting ground state with ferromagnetic ordering. Furthermore, the calculation show that it is necessary to carry out GGA+U scheme and structure optimization on this system.