Simple method for determining binding energies of fullerene and complex atomic negative ions.

A robust potential which embeds fully the vital core polarization interaction has been used in the Regge pole method to explore low-energy electron scattering from C$_{\mathrm{60}}$, Eu and Nb through the total cross sections (TCSs) calculations. From the characteristic dramatically sharp resonances in the TCSs manifesting negative ion formation in these systems, we extracted the binding energies for the C$_{\mathrm{60}}$\textasciimacron , Eu\textasciimacron and Nb\textasciimacron anions; they are found to be in outstanding agreement with the measured electron affinities of C$_{\mathrm{60}}$[1], Eu[2, 3] and Nb[4]. Common among these considered systems, including the standard atomic Au is the formation of their ground state negative ions at the second Ramsauer-Townsend (R-T) minima of their TCSs. Indeed, this is a signature of all the fullerenes and complex atoms considered thus far. Shape resonances, R-T minima and binding energies of the resultant anions are presented. [1] D. --L. Huang\textit{ et al. }J. Chem. Phys. \textbf{140,} 224315 (2014) [2] S. -B. Cheng and A.W. Castleman, Jr., Sci. Rep. \textbf{5}, 12414 (2015) [3] V. T. Davis and J. S. Thompson, J. Phys. B \textbf{37}, 1961 (2004) [4] Z. Luo \textit{et al}. Phys. Rev. A \textbf{93}, 020501(R) (2016)