Calculated isomeric populations of Er@C82

Abstract

Relative populations of the four energy-lowest IPR (isolated-pentagon-rule) isomers of Er@C82 under the high-temperature synthetic conditions are computed using the Gibbs energy based on characteristics from the density functional theory calculations (B3LYP/6-31+G*∼SDD energetics, B3LYP/6-31G*∼SDD entropy). Two leading isomers are predicted - Er@ C 2 v ( 9 ) -C82 and Er@ C s ( 6 ) -C82. The calculated equilibrium isomeric relative populations agree with available observations. As Er@C82 is one of the metallofullerenes recently used as dopants for improvement of efficiency and stability of perovskite solar cells, the calculations should help in finding rules for further selections of fullerene endohedrals for such new applications in photovoltaics.