Molecular dynamics simulation of the oscillatory behaviour and vibrational analysis of an adamantane molecule encapsulated in a single-walled carbon nanotube

In this study, we employed classical molecular dynamics to simulate the encapsulation and examine the dynamical behaviour of an adamantane molecule inside a single-walled carbon nanotube. As a result, we found that the critical and optimal diameters of the tube for molecular encapsulation were about 9.5 and 10.86 Å, respectively, and that the speed of encapsulation mainly depended on tube’s diameter. Furthermore, the encapsulated adamantane molecule exhibited irregular motion and frequent collisional motion along the tube’s longitudinal axis and on the tube’s cross-sectional plane, respectively. In addition, we examined the influence of the tube diameter and temperature on the mean free path and average collisional frequency of the molecule’s motion. Lastly, the influence of the host–guest interaction on the systematic vibrational optic mode was studied using density functional theory calculation.