title: An approach to the electronic structure of molecular junctions with metal clusters of atomic thickness.
abstract: TD-DFT calculations predict a linear dependence of the energies of charge transfer states of Agn-pyrazine-Agnmolecular junctions on the inverse of the size (1/n) of the linear metal chains. The density of charge (qeff= q/n) in the metal-to-metal charge transfer excited states (CTMM: Agnq-pyrazine-Agn-q) smoothly tunes the electronic structure of the junction, especially the metal-to-molecule charge transfer states (CT0and CT1) and the first excited singlet of pyrazine (S1,Pz). In enlarged junctions, pyrazine bonds preferably to one of the Agnclusters and this weak adsorption produces a significant unexpected asymmetry for forward and reverse charge transfer processes.
authors.affiliation: Universidad de Málaga, Andalucía Tech, Facultad de Ciencias, Departamento de Química Física, Unidad Asociada CSIC, 29071-Málaga, Spain. jc_otero@uma.es avila@uma.es.
authors.forename: Daniel
authors.initials: D
authors.lastname: Aranda
authors.affiliation: Universidad de Málaga, Andalucía Tech, Facultad de Ciencias, Departamento de Química Física, Unidad Asociada CSIC, 29071-Málaga, Spain. jc_otero@uma.es avila@uma.es.
authors.forename: Isabel
authors.initials: I
authors.lastname: López-Tocón
authors.affiliation: Universidad de Málaga, Andalucía Tech, Facultad de Ciencias, Departamento de Química Física, Unidad Asociada CSIC, 29071-Málaga, Spain. jc_otero@uma.es avila@uma.es.
authors.forename: Juan
authors.initials: J
authors.lastname: Soto
authors.affiliation: Universidad de Málaga, Andalucía Tech, Facultad de Ciencias, Departamento de Química Física, Unidad Asociada CSIC, 29071-Málaga, Spain. jc_otero@uma.es avila@uma.es.
authors.forename: Juan C
authors.identifier: http://orcid.org/0000-0003-4078-6258
authors.initials: JC
authors.lastname: Otero
authors.affiliation: Universidad de Málaga, Andalucía Tech, Facultad de Ciencias, Departamento de Química Física, Unidad Asociada CSIC, 29071-Málaga, Spain. jc_otero@uma.es avila@uma.es.
authors.forename: Francisco
authors.identifier: http://orcid.org/0000-0003-4839-4785
authors.initials: F
authors.lastname: Avila