Electron-phonon interactions in transition metal oxides in the framework of DFT+U

First-principles approaches for computing electron-phonon (e-ph) interactions enable quantitative studies in a wide range of solids. However, e-ph interactions in many transition-metal oxides (TMOs) remain challenging to treat due to the dominant on-site Coulomb repulsion from open-shell d electrons. Here we develop calculations of e-ph interactions within the framework of Hubbard-corrected density functional perturbation theory (so-called DFPT+U), which can describe the linear response of TMOs and provide an improved treatment of electron self-interactions. Employing a Hubbard U parameter computed ab initio, we demonstrate fully first-principles calculations of the e-ph coupling and the resulting electron spectral functions in various TMOs. While standard DFT e-ph calculations lead to unphysically divergent e-ph coupling, DFT+U restores the correct physics, giving well-behaved e-ph matrix elements that properly include the Frohlich interaction. Our results highlight the key role of the Hubbard U term on e-ph interactions. They further provide a broadly applicable method for predicting e-ph interactions and transport properties in TMOs with localized open-shell d electrons.