title: Quantum Features of Anionic Species He*⁻ and He₂*⁻ in Small He(N) Clusters.
abstract: We present variational calculations on systems containing a few boson helium atoms attached to electronically excited atomic and molecular helium anions He*⁻ and He₂*⁻ and characterize their structures and energetics. Previously reported high-level ab initio results [Huber, S. E.; Mauracher, A. Mol. Phys. 2014, 112, 794] to describe the interactions between excited (metastable) anions and a neutral He atom have been employed. For the case of the atomic species He*⁻, the corresponding interaction with He suggests large anharmonicity effects due to the presence of a deep well of ∼17,500 cm⁻¹ at short distances, together with a more external shallow secondary well of ∼4 cm⁻¹, both supporting bound levels. Moreover, when a sum of pairwise interactions is assumed to describe the full PES corresponding to the presence of several neutral He atoms, geometrical constraints already predict the complete solvation of the anionic impurity by six helium atoms, giving rise to a bipyramidal structure. In turn, for the anisotropic weak interaction He-He₂*⁻, where the anionic dimer is considered as a rigid rotor, the obtained structures show the tendency of the helium atoms to pack themselves together and largely far away from the dopant, thereby confirming the heliophobic character of He₂*⁻.
authors.affiliation: Instituto de Fı́sica Fundamental, IFF-CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Villarreal
authors.affiliation: Instituto de Fı́sica Fundamental, IFF-CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Rodríguez-Cantano
authors.affiliation: Instituto de Fı́sica Fundamental, IFF-CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: Tomás
authors.initials: T
authors.lastname: González-Lezana
authors.affiliation: Instituto de Fı́sica Fundamental, IFF-CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: Rita
authors.initials: R
authors.lastname: Prosmiti
authors.affiliation: Instituto de Fı́sica Fundamental, IFF-CSIC , Serrano 123, 28006 Madrid, Spain.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Delgado-Barrio
authors.affiliation: Institute of Ion Physics, The University of Innsbruck , Technikerstrasse 25, 6020 Innsbruck, Austria.|Scuola Normale Superiore ,Piazza dei Cavalieri 7, 56126 Pisa, Italy.
authors.forename: Franco A
authors.initials: FA
authors.lastname: Gianturco