Penetrating probability and cross section of the Li-C encapsulation process through an ab initio molecular dynamics investigation.

The endohedral complex system of Li-C has been shown to possess interesting applications in photovoltaics, supramolecular chemistry, and functionalized materials. In this study, we perform a theoretical investigation of Li encapsulation within a C cage by employing an ab initio molecular dynamics approach. The Li cation is positioned 9 Å away from the C center of mass, and fired towards a randomized spot in a six-membered ring with a certain level of inletting energy, which is 7.5 eV, 9 eV, 12 eV, or 15 eV. In total, 2000 samples of MD trajectories are investigated. Our statistical results yielded a penetrating probability in the range of 0.8% to 15.6% with respect to the above inletting energy, while the cross section ranges from 0.006 Å to 0.123 Å. Moreover, we observed that the penetrating probability exhibited direct proportionality to the inletting energy. Hence, we can determine that the minimum required inletting energy for reaction occurrence is 6.6 eV. Overall, it seems difficult for Li to penetrate through the sp-carbon wall, because a very high inletting energy is required to open the entrance. At the same time, Li must approach closely to the center of a six-membered ring to enhance the penetration probability.