Abstract

Density-functional theory (DFT) with extended Hubbard functionals is a powerful method for studying complex materials containing transition-metal and rare-earth elements, owing to its accuracy in correcting self-interaction errors and its low computational cost. Recently, we developed an automated and reliable approach for the first-principles self-consistent determination of the on-site U and inter-site V Hubbard parameters using density-functional perturbation theory [1-3]. I will show how this formalism can be used for the calculation of properties such as voltages in Li-ion batteries and formation energies of oxygen vacancies in perovskites. Additionally, I will discuss the applicability of this formalism for improving band gaps with respect to standard DFT and its use for searching for novel materials for photocatalytic water splitting. Finally, I will present the extension of this framework to the calculations of phonons and electron-phonon coupling in selected transition-metal compounds. These tools are implemented in the open-source Quantum ESPRESSO distribution [4] and are available to the community at large. [1] I. Timrov, N. Marzari, M. Cococcioni, Phys. Rev. B 98 , 085127 (2018). [2] I. Timrov, N. Marzari, M. Cococcioni, Phys. Rev. B 103 , 045141 (2021). [3] I. Timrov, N. Marzari, M. Cococcioni, Comput. Phys. Commun. 279, 108455 (2022). [4] P. Giannozzi et al., J. Phys.: Condens. Matter 29, 465901 (2017).