Monitoring LaMnO3 Jahn–Teller distortion via electric-field gradient ab initio calculations

Abstract

The electric field gradient (EFG) is studied via ab initio density functional theory calculations for the prototype LaMnO3 manganite under ferromagnetic and A-type antiferromagnetic configurations with different values of on-site Hubbard U potential correction on the Mn-3d states. It is shown that the relaxation of internal atomic positions inhibits fully activated MnO6 Jahn–Teller distortions, as determined by calculating the EFG tensor and the Jahn–Teller distortion parameter Δ. In fact, a strong correlation between the EFG values, especially at the La site, and the Jahn–Teller distortion was found and used to confirm the importance of an appropriate description of the electron–electron correlations when predicting the ground state properties of LaMnO3 using a GGA + U approximation for the exchange-correlation functional.