Metal Cluster Electrides: a new Type of Molecular Electrides with Delocalised Polyattractor Character

Abstract

Electrides are ionic substances that present isolated electrons. These confined electrons are topologically characterised by a quasiatom, i.e. a non-nuclear attractor (NNA) of the electron density. The electronic structure of octahedral 4A1g Li6+ and 5A1g Be6 species shows that these species have a large number of NNAs. These NNAs present highly delocalised electron densities and, as a result, the chemical bonding pattern of these systems reminds that of the solid metals where metal cations are surrounded by a 'sea' of delocalised valence electrons. We propose the term metal cluster electrides to refer to this new type of compounds. In this study, we establish a computational protocol to identify, characterize, and design metal cluster electrides and we elucidate the intricate bonding patterns of this particular type of species