Impact of on-site and inter-site Coulomb interactions on the electronic, magnetic and thermomagnetic properties of LaFeO3: Insights from DFT + U and DFT + U + V

LaFeO3, a widely studied antiferromagnetic perovskite oxide with complex electronic and magnetic interactions, remains a challenging system for accurate theoretical modeling. In this study, we investigate its structural, electronic, magnetic, and thermomagnetic properties using density functional theory (DFT) within the GGA, GGA + U, and GGA + U + V frameworks, which account for both on-site and inter-site electron correlations. We extract Heisenberg exchange parameters from the total energies of various magnetic configurations to construct a Heisenberg Hamiltonian, and then estimate transition temperatures via classical Monte Carlo simulations. The on-site (U) and inter-site (V) interaction parameters are computed self-consistently using linear response theory. Then, a quantum correction is applied to the Monte Carlo results, which significantly improves results towards the experimental data (MAPE ≈ 6 %). This work proposes that combining GGA + U + V with quantum-corrected Monte Carlo calculations is a good approach to tackling the thermomagnetic behavior of strongly correlated oxides, like LaFeO3.