Ground and Electronically Excited States of Main-Group-Metal-Doped B₂₀ Double Rings

Abstract

Ab initio coupled-cluster, electron propagator, and Møller–Plesset second-order perturbation theory calculations are utilized to analyze the low-lying electronic states of several metal-doped B20. In the ground state, the presently focused AB20/EB20 (A = Li, Na, and K; E = Mg and Ca) consist of charge-separated A+B20 –/E2+B20 2– frameworks. The excited electronic states of AB20 and EB20 + were analyzed by computing the vertical electron attachment energies (VEAEs) of AB20 + and EB20 2+. In several excited states, the radical electron is predominantly localized on the B20 frames, which are counterparts of the low-lying states of bare B20 –. A variety of basis sets were tested on obtaining VEAEs, and the aug-cc-pVDZ/A,E d-aug-cc-pVDZ/B combination provided the best accuracy–efficiency compromise on them. Furthermore, this work analyzes the Rydberg-like excited states of AB20 and EB20 + and will serve as a guide for future studies on similar metal-doped boron systems.

Transition Metal Behavior of Heavier Alkaline Earth Elements in Doped Monocyclic and Tubular Boron Clusters

“…Previous studies have suggested that the main-group-metal-centered monocyclic rings tend to be located as local minima rather than global minima . Additionally, the heavier Ae atoms with a large radius size are usually located at the off-centered position in the tubular boron clusters . Consequently, we chose two heavier Ae atoms as dopants in the boron clusters to obtain highly symmetric and stable candidates.…”

“…67 Additionally, the heavier Ae atoms with a large radius size are usually located at the offcentered position in the tubular boron clusters. 68 Consequently, we chose two heavier Ae atoms as dopants in the boron clusters to obtain highly symmetric and stable candidates. Following the above electron counting rule (2x + 12/20/26 + 2y), four extra electrons should be counted due to the presence of two Ae atoms.…”