Jose Ulises Reveles

Multiple valence superatoms

We recently demonstrated that, in gas phase clusters containing aluminum and iodine atoms, an Al13 cluster behaves like a halogen atom, whereas an Al14 cluster exhibits properties analogous to an alkaline earth atom. These observations, together with our findings that Al13− is inert like a rare gas atom, have reinforced the idea that chosen clusters can exhibit chemical behaviors reminiscent of atoms in the periodic table, offering the exciting prospect of a new dimension of the periodic table formed by cluster elements, called superatoms. As the behavior of clusters can be controlled by size and composition, the superatoms offer the potential to create unique compounds with tailored properties. In this article, we provide evidence of an additional class of superatoms, namely Al7−, that exhibit multiple valences, like some of the elements in the periodic table, and hence have the potential to form stable compounds when combined with other atoms. These findings support the contention that there should be no limitation in finding clusters, which mimic virtually all members of the periodic table.

Hund’s rule in superatoms with transition metal impurities

The quantum states in metal clusters bunch into supershells with associated orbitals having shapes resembling those in atoms, giving rise to the concept that selected clusters could mimic the characteristics of atoms and be classified as superatoms. Unlike atoms, the superatom orbitals span over multiple atoms and the filling of orbitals does not usually exhibit Hund’s rule seen in atoms. Here, we demonstrate the possibility of enhancing exchange splitting in superatom shells via a composite cluster of a central transition metal and surrounding nearly free electron metal atoms. The transition metal d states hybridize with superatom D states and result in enhanced splitting between the majority and minority sets where the moment and the splitting can be controlled by the nature of the central atom. We demonstrate these findings through studies on TMMgn clusters where TM is a 3d atom. The clusters exhibit Hund’s filling, opening the pathway to superatoms with magnetic shells.

On the Ground State of Pd13

First-principles electronic structure calculations within a gradient corrected density functional formalism have been carried out to investigate the electronic structure and magnetic properties of Pd(13) clusters. It is shown that a bilayer ground-state structure that can be regarded as a relaxed bulk fragment is most compatible with the experimental results from Stern-Gerlach measurements. An icosahedral structure, considered to be the ground state in numerous previous studies, is shown to be around 0.14 eV above the ground state. A detailed analysis of the molecular orbitals reveals the near degeneracy of the bilayer or icosahedral structures is rooted in the stabilization by p- or d-like cluster orbitals. The importance of low-lying spin states in controlling the electronic and magnetic properties of the cluster is highlighted.

First principles study of Sc, Ti, and V doped Na n ( n = 4 , 5 , 6 ) clusters: Enhanced magnetic moments

Theoretical studies on the geometry, electronic structure, and spin multiplicity of Sc, Ti, and V doped

Anion photoelectron spectroscopy and density functional investigation of diniobium-carbon clusters.

{\mathrm{Na}}_{n}

Al12Cu Superatom as Stable Building Block of Ionic Salts

(n=4,5,6)

On the Magic Character of Al 6 Au

clusters have been carried out within a gradient corrected density functional approach. Two complementary approaches including all-electron calculations on free clusters and supercell calculations using plane-wave pseudopotential and projector augmented wave formalisms have been carried out. It is shown that spin magnetic moments of the transition metal atoms, the magnitude of host polarization, and the sign of the host polarization all change with the number of alkali atoms. In particular, the transition metal atoms are shown to attain spin moments that are higher than their atomic values. The role of hybridization between the transition atom

Experimental and Theoretical Study of the Structure and Reactivity of Fe 1 - 2 O ≤ 6 - Clusters with CO

d

Hydrogen storage in bimetallic Ti–Al sub-nanoclusters supported on graphene

states and the alkali