Endohedral boron-doped scandium clusters BSc ( = 2-3, = 3-13): triangular - linear rearrangement of the B dopant.

A theoretical investigation, employing density functional theory with the PBE functional and the Def2-TZVP basis set, comprehensively explores the geometric and electronic structures and properties of the boron doped scandium clusters BSc with = 2-3 and = 3-13. Introduction of B atoms significantly enhances the stability of the resulting clusters with respect to the initial counterparts. As the number of B atoms increases, the stability of the doped clusters improves, following the order: BSc > BSc > BSc > Sc. Notably, the B@Sc cluster represents the smallest fully endohedral doubly doped cage, and the B@Sc is the smallest fully endohedral triply doped cage reported to date. The size with 8 Sc atoms plays a crucial role in the structural evolution of both doubly doped BSc and triply doped BSc series. For the doubly doped species, this size marks an exohedral-to-endohedral transition, while in the triply doped species, it marks an interconversion of the B dopant from a triangular to a linear arrangement. In the triangular B trimer, the electron and charge distribution are evenly shared among the three B atoms, whereas in the linear B trimer, these distributions are unequal. Additionally, the geometric and electronic structures of the linear-B doped B@Sc can serve as basic building blocks for the construction of larger clusters.