<?xml version='1.0' encoding='utf-8'?> <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> <dc:creator>Gebreyesus, Garu</dc:creator> <dc:creator>Bastonero, Lorenzo</dc:creator> <dc:creator>Kotiuga, Michele</dc:creator> <dc:creator>Marzari, Nicola</dc:creator> <dc:creator>Timrov, Iurii</dc:creator> <dc:date>2023-11-30</dc:date> <dc:description>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.</dc:description> <dc:identifier>https://archive.materialscloud.org/record/2023.187</dc:identifier> <dc:identifier>doi:10.24435/materialscloud:vz-7q</dc:identifier> <dc:identifier>mcid:2023.187</dc:identifier> <dc:identifier>oai:materialscloud.org:2001</dc:identifier> <dc:language>en</dc:language> <dc:publisher>Materials Cloud</dc:publisher> <dc:rights>info:eu-repo/semantics/openAccess</dc:rights> <dc:rights>Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode</dc:rights> <dc:subject>BaTiO3</dc:subject> <dc:subject>DFT+U+V</dc:subject> <dc:subject>DFT+U</dc:subject> <dc:subject>phonons</dc:subject> <dc:subject>Raman spectra</dc:subject> <dc:subject>CSCS</dc:subject> <dc:subject>MARVEL/P4</dc:subject> <dc:title>Understanding the role of Hubbard corrections in the rhombohedral phase of BaTiO₃</dc:title> <dc:type>Dataset</dc:type> </oai_dc:dc>