Metal-insulator transition and lattice instability of paramagnetic V2O3

We determine the electronic structure and phase stability of paramagnetic V2O3 at the Mott-Hubbard metal-insulator transition (MIT) by employing a combination of an ab initio method for calculating band structures with dynamical mean-field theory. The structural transformation associated with the MIT occurs upon a slight expansion of the lattice volume by similar to 1.5%, in agreement with experiment. Our results show that the structural transition precedes the MIT, implying a complex interplay between electronic and lattice degrees of freedom. The MIT is found to be driven by a strong correlation-induced, orbital-selective renormalization of the V t(2g) bands. The effective electron mass of the e(g)(pi) orbitals diverges at the MIT. Our results show that full charge self-consistency is crucial for a correct description of the physical properties of V2O3.