A New Hole Density as a Stability Measure for Boron Fullerenes

TL;DR

This paper introduces a new hole density measure to evaluate the stability of boron fullerenes, linking cage geometry to energetic stability through first-principles calculations.

Contribution

It proposes a novel hole density definition and demonstrates its effectiveness as a stability indicator for boron fullerenes.

Findings

Most stable cages have similar normalized hole densities.

Larger differences in hole densities correlate with increased stability.

The new measure relates cage geometry to energy stability.

Abstract

We investigate the stability of boron fullerene sets B76, B78 and B82. We evaluate the ground state energies, nucleus-independent chemical shift (NICS), the binding energies per atom and the band gap values by means of first-principles methods. We construct our fullerene design by capping of pentagons and hexagons of B60 cage in such a way that the total number of atoms is preserved. In doing so, a new hole density definition is proposed such that each member of a fullerene group has a different hole density which depends on the capping process. Our analysis reveal that each boron fullerene set has its lowest-energy configuration around the same normalized hole density and the most stable cages are found in the fullerene groups which have relatively large difference between the maximum and the minimum hole densities. The result is a new stability measure relating the cage geometry characterized by the hole density to the relative energy.