Characterization of Electronic States inside Metallic Nanopores
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Previous work has shown that unusual chemistry can be induced inside metallic slit nanopores. This phenomenon has been attributed to the presence of an enhanced electronic density within the pore. Here we use ab initio density functional theory and post-Hartree-Fock correlated methods to characterize the electronic density in the gap defined by two parallel metallic surfaces. In the first part of this work, the electronic density of states of several transition metal nanopores is calculated for different pore sizes (i.e., surface-surface separations). Results show the existence of a critical surface-surface separation below which electronic states corresponding to the gap between surfaces become populated at energies below the Fermi level of the metal, leading to the presence of electrons in the pore. Further reduction in the nanopore size increases the number of states corresponding to the gap, which agrees with the increasingly higher electronic densities found in the gap for smaller surface-surface separations. In the second part of this work, the presence of electrons in the gap between two finite platinum layers (each layer composed of 4-13 atoms) is assessed using density functional theory and correlated ab initio methods, to analyze the dependence of the electronic density observed in these nanopores on the computational method employed. 2013 American Chemical Society.