Studying the occupied and unoccupied electronic structure of LaCoO${}_3$ by using DFT+embedded DMFT method with the calculated value of $\text{U}$

Abstract

In this work, we present a systematic study of the occupied and unoccupied electronic states of LaCoO${}_3$ compound using DFT, DFT+$\text{U}$ and DFT+embedded DMFT methods. The value of $\text{U}$ used here is evaluated by using constrained DFT method and found to be $\backsim$ 6.9 eV. It is found that DFT result has limitations with energy positions of PDOS peaks due to its inability of creating a hard gap although the DOS distribution appears to be fine with experimental attributes. The calculated value of $\text{U}$ is not an appropriate value for carrying out DFT+$\text{U}$ calculations as it has created an insulating gap of $\backsim$ 1.8 eV with limitations in redistribution of DOS which is inconsistent with experimental spectral behaviour for the occupied states mainly. However, this value of $\text{U}$ is found to be an appropriate one for DFT+embedded DMFT method which creates a gap of $\backsim$ 1.1 eV. The calculated PDOS of Co 3$\text{d}$, La 5$\text{d}$, La 4$\text{f}$ and O 2$\text{p}$ states are giving a remarkably good explanation for the occupied and unoccupied states of the experimental spectra in the energy range $\backsim$ -9.0 eV to $\backsim$ 12.0 eV.

References in corpus (10)

• Quantum Monte Carlo Impurity Solver for Cluster DMFT and Electronic Structure Calculations in Adjustable Base
• Calculations of Hubbard U from first-principles
• Construction and solution of a Wannier-functions based Hamiltonian in the pseudopotential plane-wave framework for strongly correlated materials
• Spin state transition and covalent bonding in LaCoO3
• Disproportionation and Metallization at Low-Spin to High-Spin Transition in Multiorbital Mott Systems
• Importance of exchange-anisotropy and superexchange for the spin-state transitions in LnCoO3 (Ln=La,Y,RE) cobaltates
• Coulomb correlations intertwined with spin and orbital excitations in LaCoO${}_3$
• Density functional plus dynamical mean field theory of the metal-insulator transition in early transition metal oxides
• Electronic structure of BaIrO3: A first principle study using local spin-density approximations
• Investigation of unoccupied electronic states of LaCoO${}_3$ and PrCoO${}_3$ using inverse photoemission spectroscopy and GGA + $U$ calculations

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• A detailed electronic structure study of Vanadium metal by using different beyond-DFT methods
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• Understanding the temperature and pressure dependent electronic properties of FeSi: DFT+DMFT study