Dynamic motion of La atom inside the C₇₄ (D₃h) cage: a relativistic DFT study.

The interaction between lanthanum atom (La) and C74 (D 3h) was investigated by all-electron relativistic density function theory (DFT). With the aid of the representative patch of C74 (D 3h), we studied the interaction between C74 (D 3h) and La and obtained the interaction potential. Optimized structures show that there are three equivalent stable isomers, with La located about 1.7 Å off center. There is one transition state between every two stable isomers. According to the minimum energy pathway, the possible movement trajectory of La atoms in the C74 (D 3h) cage was explored. The calculated energy barrier for La atoms moving from the stable isomer to the transition state is 18.4 kcal mol(-1). In addition, the dynamic NMR spectra of La@C74 according to the trajectory was calculated.