Density functional study of geometrical, electronic and magnetic properties of Wn clusters (n = 2–16, 19, 23)

SAMANTA M. CARRIÓN; REINALDO PIS DIEZ; FAUSTINO AGUILERA GRANJA

EUROPEAN PHYSICAL JOURNAL D

SPRINGER

Lugar: Berlin; Año: 2013 vol. 67 p. 3 - 11

1434-6060

Geometrical, electronic and magnetic properties of Wn atomic clusters, with n = 1–16, 19, 23,are explored using different generalized gradient approximations to the density functional theory and basissets of double-ζ quality augmented with polarization functions. From a geometrical point of view, tungstenaggregates with n = 15 and above exhibit a clear tendency to adopt structures derived from the body-centered cubic system. Total energy second-differences indicate that tungsten octamer becomes a speciallystable isomer. For larger sizes, the different generalized gradient approximations do not predict the samestability pattern. Vertical ionization energies show a smooth, but slow trend to the experimental workfunction of polycrystalline tungsten. Vertical electron affinities agree very well with experimental measuresof detachment electron energies. Calculated magnetic moments indicate that mainly singlet, triplet andquintet electronic states characterize small tungsten aggregates. A W15 isomer with a geometry derivedfrom the body-centered cubic system, however, is characterized by an electronic state with 14 unpairedelectrons.