LaMn7O12, a quadruple perovskite oxide (AA'3B4O12-type), has attracted attention for its notable bifunctional activity in oxygen evolution and reduction reactions. Here, we systematically investigate the magnetic phase diagram and lattice dynamics of LaMn7O12 using two density functional theory plus Hubbard U (DFT + U) approaches: the spin-density and the charge-only-density formalism. Phase diagram analysis as a function of U and J shows that both methods stabilize the experimentally observed antiferromagnetic (AFM) configuration (C-type AFM at the B-site and ferrimagnetic structure at the A'-site Mn ions) at U = 3.5 eV and J = 0.8 eV. These U and J values are consistent with those obtained from the constrained random phase approximation. Furthermore, we observe the dynamical stability of the AFM phase through phonon dispersion curves and analyze the Raman-active phonon modes. These results highlight the critical role of appropriate U and J parameters in accurately describing the properties of LaMn7O12.
@article{arxiv.2509.15665,
title = {Correlation Effects on Magnetic Structure and Lattice Dynamics of LaMn$_7$O$_{12}$: A First-Principles Study},
author = {Haeyoon Jung and Indukuru Ramesh Reddy and Bongjae Kim and Jiyeon Kim and Sooran Kim},
journal= {arXiv preprint arXiv:2509.15665},
year = {2026}
}