Electron localization in a one-dimensional nanoscopic system: A combined exact diagonalization - an ab initio approach - art. no. 161105

Exact ground-state properties are presented by combining the diagonalizatio n in the Fock space (and taking all hopping integrals and all two-site inte ractions) with the ab initio optimization of the Wannier functions. Electro ns are essentially localized for the interatomic distance R similar to2.0 A ngstrom for s-like states, when the quasiparticle mass is divergent. The mo mentum distribution dispersion is proposed to define the localization order parameter. Dimerization and zero-point energies are also discussed. The me thod provides convergent results for N greater than or equal to -8 atoms.