Anion Photoelectron Spectroscopy of Vanadium-Doped Cobalt Clusters

A Density Functional Theory Investigation of the Bimetallic Clusters Nb2Rh and NbRh2 and the Complexes They Form with CO

The interaction of CO with the bimetallic clusters Nb2Rh and NbRh2 has been theoretically investigated using density functional theory. The lowest energy structure of Nb2Rh is found to be a doublet Cs scalene triangle and the global minimum of Nb2Rh–CO is a dissociative structure with C1 symmetry. The lowest energy minimum of NbRh2 is found to be a doublet C2v isosceles triangle and the global minimum of NbRh2–CO is a dissociative structure with Cs symmetry. In comparison with our previous work on Rh3 + CO (J. Comp. Chem., 2008, 29, 1497), these results show that substitution of a single Rh atom with Nb is sufficient to dissociate CO.

Study of the size-dependent properties of Sc(n)Al (n = 1-14) clusters by density-functional theory

The geometries, stabilities, and electronic and magnetic properties of Sc(n)Al (n = 1-14) clusters with different spin configurations have been investigated systematically within the framework of the gradient-corrected density-functional theory. Our resulting geometries show that the aluminum atom remains on the surface of clusters with n<9, while it takes up the center of Sc-cage clusters with n≥9. Besides, the doping of Al improves the stability of the host clusters. Maximum peaks are observed for Sc(n)Al clusters at n = 3, 6, 10 and 12 with the size dependent on the second-order energy differences and fragmentation energies, implying that these clusters are relatively more stable. For all the Sc(n)Al clusters studied, we find the charge transfer from Sc to Al sites and the coexistence of ionic and covalent bonding characteristics. The doping of the Al atom induces the magnetic moments of the host clusters decrease except for n = 8 and 14 and the total magnetic moments are quenched at n = 5, 7, 9 and 11.

A density-functional study of Al-doped Ti clusters: TinAl (n=1–13)

Equilibrium geometries, stabilities, and electronic properties of TinAl (n = 1-13) clusters have been studied by using density-functional theory with local spin density approximation and generalized gradient approximation. The ground-state structures of TinAl clusters have been obtained. The resulting geometries show that the aluminum atom remains on the surface of clusters for n < 9, but is slowly getting trapped beyond n = 9, meanwhile, the Al atom exhibits a valent transition from monovalent to trivalent. The geometric effects and electronic effects clearly demonstrate the Ti4Al cluster to be endowed with special stability. The studies on the bonds indicate the change from ionic to metalliclike.