A Density Functional Study of Small Tungsten Clusters Adsorbed on the MgO(001) Surface

Metal atoms, clusters, and thin films supported on surfaces of metal oxides have attracted a lot of attention not only due to the fundamental interest in the basic nature of metal-oxide interfaces, but also because of their numerous practical applications in catalysis, microelectronics, as coatings for corrosion protection and gas-sensors^[1,2]. In this paper, adsorption of tungsten clusters W_n (n=l-4) on the ideal MgO(001) surface has been studied computationally at the density functional (DF) level of theory with the help of a scalar-relativistic variant of the linear combination of Gaussian-type. orbitals density functional method (LCGTO-DF)^[3] as implemented in the program PARAGAUSS for parallel computing^[4]. Stucture and energetic features of the adsorption complexes W_n/MgO(001) have been analyzed. The gradient-corrected Becke-Perdew functional was used self-consistently. Spin-polarized calculations were performed in order to account for the possible open-shell nature of the metal clusters.