Accurate Electron-Phonon Interactions from Advanced Density Functional Theory

Electron-phonon coupling (EPC) is key to understanding charge transport, band renormalization, and superconductivity in energy materials, including correlated transition-metal oxides, ferroelectric perovskites, optoelectronic semiconductors, and phonon-mediated superconductors. Although first-principles density functional theory (DFT)-based EPC calculations are used widely, their predictive power is limited by the accuracy, transferability, and efficiency of the underlying exchange-correlation functionals. These limitations become exacerbated in complex d - and f -electron materials, where beyond-DFT approaches and additional corrections, such as the Hubbard U , are commonly invoked. Here, using the examples of Co O and Ni O , we show how the r 2 SCAN density functional correctly captures strong EPC effects in transition-metal oxides without requiring the introduction of Hubbard U parameters. We also find that r 2 SCAN successfully describes the subtle interplay between ionic and covalent bonding, and strong EPC effects in the low-temperature rhombohedral phase of the prototypical ferroelectric Ba Ti O 3 , without requiring Hubbard U and intersite V corrections. We further demonstrate the ability of r 2 SCAN to accurately model the EPC of the main-group semiconductor Ga As and the phonon-mediated superconducting properties of Mg B 2 , with reliable electronic bands and phonons. Our study establishes r 2 SCAN-based EPC as a transferable, parameter-free, and computationally efficient framework for predictive material-specific modeling of EPC in energy materials, and opens a practical route toward high-throughput screening of superconductors, thermoelectrics, optoelectronic semiconductors, and oxide electrodes and catalysts.