2026-04-21T00:32:29Z https://archive.materialscloud.org/oai2d

oai:materialscloud.org:2001 2023-11-30T10:19:55Z openaire_data community-mcarchive

Gebreyesus, Garu Bastonero, Lorenzo Kotiuga, Michele Marzari, Nicola Timrov, Iurii Gebreyesus, Garu Bastonero, Lorenzo Kotiuga, Michele Marzari, Nicola Timrov, Iurii 2023-11-30 We present a first-principles study of the low-temperature rhombohedral phase of BaTiO₃ using Hubbard-corrected density-functional theory. By employing density-functional perturbation theory, we compute the onsite Hubbard U for Ti(3d) states and the intersite Hubbard V between Ti(3d) and O(2p) states. We show that applying the onsite Hubbard U correction alone to Ti(3d) states proves detrimental, as it suppresses the Ti(3d)-O(2p) hybridization and drives the system towards a cubic phase. Conversely, when both onsite U and intersite V are considered, the localized character of the Ti(3d) states is maintained, while also preserving the Ti(3d)-O(2p) hybridization, restoring the rhombohedral phase of BaTiO₃. The generalized PBEsol+U+V functional yields good agreement with experimental results for the band gap and dielectric constant, while the optimized geometry is slightly less accurate compared to PBEsol. Zone-center phonon frequencies and Raman spectra are found to be significantly influenced by the underlying geometry. PBEsol and PBEsol+U+V provide satisfactory agreement with the experimental Raman spectrum when the PBEsol geometry is used, while PBEsol+U Raman spectrum diverges strongly from experimental data highlighting the adverse impact of the U correction alone in BaTiO₃. Our findings underscore the promise of the extended Hubbard PBEsol+U+V functional with first-principles U and V for the investigation of other ferroelectric perovskites with mixed ionic-covalent interactions. application/x-tar text/plain application/octet-stream text/plain text/markdown https://doi.org/10.24435/materialscloud:vz-7q oai:materialscloud.org:2001 mcid:2023.187 eng Materials Cloud https://arxiv.org/abs/2309.04348 https://doi.org/10.1103/PhysRevB.108.235171 https://renkulab.io/projects/new?data=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 https://archive.materialscloud.org/communities/mcarchive https://doi.org/10.24435/materialscloud:6x-8g info:eu-repo/semantics/openAccess Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode BaTiO3 DFT+U+V DFT+U phonons Raman spectra CSCS MARVEL/P4 Understanding the role of Hubbard corrections in the rhombohedral phase of BaTiO₃ info:eu-repo/semantics/other