The dynamic motion of a M (M = Ca, Yb) atom inside the C74 (D 3h) cage: a relativistic DFT study

The interaction between M (M?=?Ca, Yb) atom and C₇₄ (D _3h) has been investigated by all electron relativistic density function theory. With the aid of the representative patch of C₇₄ (D _3h), we studied the interaction between C₇₄ (D _3h) and M (M?=?Ca, Yb) atom and obtained the interaction potential. Optimized structures show that there are three equivalent stable isomers and there is one transition state between every two stable isomers. According to the minimum energy pathway, the possible movement trajectory of M (M?=?Ca, Yb) atom in the C₇₄ (D _3h) cage is explored. The calculated energy barrier for Yb atoms moving from the stable isomer to the transition state is 10.4 kcal mol^?1 and the energy barrier for Ca atoms is 6.1 kcal mol^?1. The calculated NMR spectra of M@C₇₄ (M?=?Ca, Yb) are in good agreement with the experimental data. There are nine lines in the spectra: one 1/6 intensity signal, four half intensity signals and four full intensity signals.