Investigation of metal-insulator like transition through the ab initio density matrix renormalization group approach

Abstract

We have studied the Metal-Insulator like Transition (MIT) in lithium and beryllium ring-shaped clusters through ab initio Density Matrix Renormalization Group (DMRG) method. Performing accurate calculations for different interatomic distances and using Quantum Information Theory (QIT) we investigated the changes occurring in the wavefunction between a metallic-like state and an insulating state built from free atoms. We also discuss entanglement and relevant excitations among the molecular orbitals in the Li and Be rings and show that the transition bond length can be detected using orbital entropy functions. Also, the effect of different orbital basis on the effectiveness of the DMRG procedure is analyzed comparing the convergence behavior.