Molecular dynamics of He encapsulation in the C₂₀H₂₀ cage at the threshold energy

Abstract

The encapsulation of He inside C₂₀H₂₀ cage has been investigated in the framework of molecular dynamics for incident atom energy in a range close to the threshold value, corresponding to the projectile passing through the pentagonal carbon ring. The entrance of He atom into dodecahedrane is analyzed in terms of static and dynamic potential barriers. The details of helium capture inside the molecular box is revealed by using geometric and energetic parameters, being associated with the response of the atomic configuration near the collision site on the C₂₀H₂₀ cage. The energy transferred from the incident atom to deformation, vibrations, and recoil of the molecule target, was calculated as a function of the distance between the projectile and the collision site on C₂₀H₂₀ cage. The calculations show that the noble gas atom, encapsulated at the threshold of 315.62 Å/ps, oscillates across the void of the dodecahedrane with frequencies of 2.5, 22.5, and 25.0 THz, monitored for a time interval of 10 ps starting at helium penetration into C₂₀H₂₀. Molecular dynamics calculations are based on ab-initio Hartree-Fock method, considering an adiabatic process. This study reveals advantageous features of helium encapsulation in dodecahedrane molecules in designing super-molecular structures for advanced nano sensors in the field of THz detectors.

Keywords:

• ab initio molecular dynamics
• He-C₂₀H₂₀ collision
• endohedral dodecahedrane
• noble gas atom oscillator

Disclosure statement

The authors declare no conflict of interest.