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: Orsay; Año: 2013 vol. 67 p. 3 - 9

1434-6060

Abstrac. Geometrical, electronic and magnetic properties of Wn atomic clusters, with n=2-16, 19, 23, are explored using different generalized gradient approximations to the density functional theory and basis sets of doublé- ξ quality augmented with polarization functions. From a geometrical point of view, tungsten aggregates 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 specially stability pattern.b Vertical ionization energies show a smooth, but slow trend to the experimental work function of pollycrystalline tungsten. Vertical electron affinities agree very well with experimental measures of detachment electron energies. Calculated magnetic moments indicate that mainly singlet, triplet and quintet electronic states characterize small tungsten aggregates. A W15 isomer with a geometry derived from the body-centered cubic system, however, is characterized by an electronic state with 14 unpaired.