GW for transition metal oxide perovskites

The \emph{ab initio} calculation of quasiparticle (QP) energies is a technically and computationally challenging problem. In condensed matter physics the most widely used approach to determine QP energies is the $GW$ approximation. Although the $GW$ method has been widely applied to many typical semiconductors and insulators, its applications to more complex compounds such as $4d$ and $5d$ (and to a lesser extent 3$d$) perovskites, have been comparatively rare, and its proper use is not well established from a technical point of view. In this work, we have applied the $GW$ method to a representative set of transition-metal perovskites including 3$d$, 4$d$ and 5$d$ compounds with different electron occupancies, magnetic ordering and structural characteristics. We will discuss the proper procedure to obtain converged QP energies and accurate bandgaps, and highlight the difference between norm-conserving and ultrasoft potentials in GW calculations.