Revisiting the trapping of noble gases (He–Kr) by the triatomic H3+ and Li3+ species: a density functional reactivity theory study

Abstract

Small atomic clusters with exotic stability, bonding, aromaticity and reactivity properties can be made use of for various purposes. In this work, we revisit the trapping of noble gas atoms (He -Kr) by the triatomic H3 + and Li3 + species by using some analytical tools from density functional theory, conceptual density functional theory, and the information-theoretic approach. Our results showcase that though similar in geometry, H3 + and Li3 + exhibit markedly different behaviour in bonding, aromaticity, and reactivity properties after the addition of noble gas atoms. Moreover, the exchange-correlation interaction and steric effect are key energy components in stablizing the clusters. This study also finds that the origin of the molecular stability of these species is due to the spatial delocalization of the electron density distribution. Our work provides an additional arsenal towards better understanding of small atomic clusters capturing noble gases.

The three-center two-positron bond

“…Additionally, to explain the relative stability and structure of Li 3 + , the presence of σ-aromatic or σ-antiaromatic states is still widely discussed. 47,49–51 Based on the reported similarities of the bonding densities of 2e + [H 3 3− ] and Li 3 + , we speculate that the positrons in 2e + [H 3 3− ] could also be considered as ‘pseudo’-metallic in character and that the positronic delocalization in 2e + [H 3 3− ] could provide in the future evidence of a new type of positronic σ-aromaticity or σ-antiaromaticity. Exploring the extension of the metallic bond and aromaticity concepts to positronic molecules would require a more in-depth analysis of the bonding nature.…”