Isotope effect in the Mott transition; a prediction on the basis of molecular all-quantum simulations

We have linked an ab initio Hartree-Fock Hamiltonian to the Feynman path in tegral quantum Monte Carlo formalism in order to derive electronic expectat ion values under consideration of nuclear degrees of freedom. This approach yields electronic expectation values which depend on the atomic masses. On the basis of combined path integral - ab initio calculations we predict an isotope effect in the correlation driven Mott transition. The nuclear degr ees of freedom lead to an enhancement in the electronic correlation strengt h, an effect which supports the transition conditions. This enhancement is negatively correlated with the atomic masses. Implications of an isotope ef fect in the Mott transition for the explanation of the superconducting pair ing are mentioned concisely.