Ng@M10H10: nobel gas trapping by an alkali hydride cage

Abstract

The stability of noble gas encapsulated M₁₀H₁₀ (M = Li, Na, K) cage structures is examined using density functional and ab initio molecular dynamics simulations. To ascertain the effectiveness of M₁₀H₁₀ cages in encapsulating noble gas atoms, dissociation energy and dissociation enthalpy are computed. Ab initio molecular dynamics simulation shows that the systems are kinetically stable and maintain their structures over the simulation time (500 fs) at three different temperatures (300 K, 150 K, and 77 K), despite the fact that they are thermodynamically less stable or metastable with regard to the dissociation of individual Ng atoms and parent cages. The non-covalent nature of the Ng–Ng (Ng = He, Ne, Ar) interactions in Ng₂@K₁₀H₁₀ are demonstrated by electron density analysis. In every cage system, the Ng–H bonds are also found to be non-covalent in nature.