On the crystalline structure of orthorhombic SrRuO$_3$: A benchmark study of DFT functionals

Abstract

By investigating the crystalline structure of ground-state orthorhombic SrRuO$_3$, we present a benchmark study of some of the most popular density functional theory (DFT) approaches from the local density approximation (LDA), generalized-gradient approximation (GGA), and hybrid functional families. Recent experimental success in stabilizing tetragonal and monoclinic phases of SrRuO$_3$ at room temperature sheds a new light on the ability to accurately describe geometry of this material by applying first-principles calculations. Therefore, our work is aimed to analyse the performance of different DFT functionals and provide some recommendations for future research of SrRuO$_3$. A comparison of the obtained results to the low-temperature experimental data indicates that revised GGAs for solids are the best choice for the lattice constants and volume due to their nice accuracy and low computational cost. However, when tilting and rotation angles appear on the scene, a combination of the revised GGAs with the hybrid scheme becomes the most preferable option. It is important to note that a worse performance of LDA functional is somewhat compensated by its realistic reproduction of electronic and magnetic structure of SrRuO$_3$, making it a strong competitor if the physical features are also taken into account.