6533b872fe1ef96bd12d36e4

RESEARCH PRODUCT

BaCoO3 monoclinic structure and chemical bonding analysis: hybrid DFT calculations

Davis ZavickisG. ZvejnieksEugene A. KotominDenis Gryaznov

subject

education.field_of_studyMaterials sciencePopulationGeneral Physics and Astronomy02 engineering and technologyOrbital overlapCrystal structure010402 general chemistry021001 nanoscience & nanotechnology01 natural sciences0104 chemical sciencesCrystalCondensed Matter::Materials ScienceCrystallographyChemical bondDensity of statesCondensed Matter::Strongly Correlated ElectronsPhysical and Theoretical Chemistry0210 nano-technologyeducationGround stateMonoclinic crystal system

description

Cobalt based perovskites have great potential for numerous applications. Contrary to a generally assumed hexagonal space group (SG P63/mmc) model as the ground state of BaCoO3 (BCO), our hybrid DFT calculations with B1WC density functional and the symmetry group–subgroup derived crystal structure model support the ground state of BCO to be indeed monoclinic, in agreement with recent experimental predictions [Chin et al., Phys. Rev. B, 2019, 100, 205139]. We found for the monoclinic BCO that the C-type anti-ferromagnetic low-spin (AFM LS) state (SG P2/c) is energetically only slightly more preferential at 0 K than the ferromagnetic (FM) LS state (SG C2/c). In turn, these monoclinic structures are energetically more favourable than the hexagonal ones, due to slight z-axis tilting. The analysis of density of states (DOS) and crystal orbital overlap population (COOP) shows a significant (almost 2 eV) separation between occupied and empty t2g states (in the spin-down channel and corresponding anti-bonding states) induced by the z-axis tilting.

https://doi.org/10.1039/d1cp01900g