Pressure-Induced Metal-Insulator Transition inLaMnO3Is Not of Mott-Hubbard Type

Calculations employing the local density approximation combined with static and dynamical mean field theories ($\mathrm{LDA}+U$ and $\mathrm{LDA}+\mathrm{DMFT}$) indicate that the metal-insulator transition observed at 32 GPa in paramagnetic ${\mathrm{LaMnO}}_3$ at room temperature is not a Mott-Hubbard transition, but is caused by orbital splitting of the majority-spin $e_g$ bands. For ${\mathrm{LaMnO}}_3$ to be insulating at pressures below 32 GPa, both on-site Coulomb repulsion and Jahn-Teller distortion are needed.