Abstrakt
Computations of the molecular parameters and relative populations are reported for the two isomers of Er(3)N@C(80) experimentally known, i.e. produced by encapsulation into the isolated-pentagon-rule (IPR) C(80) cages with I(h) and D(5h) symmetries. The calculations are mostly based on the density-functional theory (DFT) treatments with the B3LYP functional.
However, the inter-isomeric energetics is further refined with the B2PLYP method which places the D(5h) endohedral higher in the potential energy by 18.8 kcal/mol. The isomeric populations are evaluated using the Gibbs energy in a broad temperature interval.
The computations performed with the floating-encapsulate-model (FEM) treatment agree with the observation that Er(3)N@I(h) (7)-C(80) represents the major isomer. The calculations also suggest some similarity between Er(3)N@C(80) and Lu(3)N@C(80) so that Er(3)N@C(80) could possibly also produce a useful nanowire, like recently found with Lu(3)N@C(80) and its interesting electrical-conductivity and switching behavior.