<?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>Merkel, Maximilian E.</dc:creator> <dc:creator>Ederer, Claude</dc:creator> <dc:date>2021-10-29</dc:date> <dc:description>We explore the transition to a charge-disproportionated insulating phase in a five-orbital cubic tight-binding model applicable to transition-metal perovskites with a formal d^4 occupation of the transition-metal cation, such as ferrates or manganites. We use dynamical mean-field theory to obtain the phase diagram as a function of the average local Coulomb repulsion U and the Hund's coupling J. The main structure of the phase diagram follows from the zero band-width (atomic) limit and represents the competition between high-spin and low-spin homogeneous and an inhomogeneous charge-disproportionated state. This results in two distinct insulating phases: the standard homogeneous Mott insulator and the inhomogeneous charge-disproportionated insulator, recently also termed Hund's insulator. We characterize the unconventional nature of this Hund's insulating state. Our results are consistent with previous studies of two- and three-orbital models applicable to isolated t2g and eg subshells, respectively, with the added complexity of the low-spin/high-spin transition. We also test the applicability of an effective two-orbital (eg-only) model with disordered S=3/2 t2g core spins. Our results show that the overall features of the phase diagram in the high-spin region are well described by this simplified two-orbital model but also that the spectral features exhibit pronounced differences compared to the full five-orbital description.</dc:description> <dc:identifier>https://archive.materialscloud.org/record/2021.184</dc:identifier> <dc:identifier>doi:10.24435/materialscloud:3s-b5</dc:identifier> <dc:identifier>mcid:2021.184</dc:identifier> <dc:identifier>oai:materialscloud.org:1060</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>dynamical mean-field theory</dc:subject> <dc:subject>metal-insulator transition</dc:subject> <dc:subject>charge disproportionation</dc:subject> <dc:subject>MARVEL/DD5</dc:subject> <dc:title>Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to d^4 perovskites</dc:title> <dc:type>Dataset</dc:type> </oai_dc:dc>