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The interaction between graphene layers is analyzed combining local orbital DFT and second order perturbation theory. For this purpose we use the Linear Combination of Atomic Orbitals -Orbital Occupancy (LCAO-OO) formalism, that allows us to separate the interaction energy as a sum of a weak chemical interaction between graphene layers plus the van der Waals interaction [1]. In this work, the weak chemical interaction is calculated by means of corrected-LDA calculations using an atomic-like sp3d5 basis set. The van der Waals interaction is calculated by means of second order perturbation theory using an atom-atom interaction approximation and the atomiclike orbital occupancies. We also analyze the effect of dynamical screening in the van der Waals interaction using a simple model. We find that this dynamical screening reduces the van der Waals energy between graphene layers by 22 meV/atom , which represents a 40% reduction in the van der Waals interaction. Taking into account this dynamical screening, we obtain a graphene-graphene interaction of 64 meV/atom, in good agreement with the experimental evidence. 2 Fil: Dappe, Y. J.. Service de Physique de l´etat Conndensé. DSM/IRAMIS/SPEC; Francia Fil: Bolcatto, Pablo Guillermo. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina. Universidad Nacional del Litoral. Facultad de Ingenieria Quimica. Departamento de Fisica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Flores, F.. Universidad Autónoma de Madrid; España Fil: Ortega, J.. Universidad Autónoma de Madrid; España |
