ab-Initio and DFT study of HCN: Role of temperature for the formation of HCN molecule in the interstellar medium

In the recent studies it is observed that not only ion/radical-molecule gas-phase reactions, but also solid-state reactions on icy dust grains play an important role for the formation of new species. Molecular hydrogen (H-2) is the most abundant molecule in the interstellar medium (ISM) in gas phase and it has been assumed to exist in solid state or as coating on grains. The work is mainly focused on the hydrogenation of CN radical in interstellar ice analogs for astronomically relevant temperatures. The solid H-2 can act as a hydrogenation agent, reacting with CN radicals to form HCN. Hydrogenation reactions of CN radical have been studied by Hartree-Fock (HF) and Density Functional Theory (DFT) methods. We have discussed that, how molecules form when CN containing ices are exposed to thermal hydrogen atoms. The present work deals with possibility of the formation of HCN by hydrogenation via radical molecule reactions in gas phase as well as in PCM and the effect of temperature on thermodynamical parameter. (C) 2021 Published by Elsevier B.V.

Automated summary

Recent studies show that solid-state reactions on icy dust grains are important for the formation of new species, including the hydrogenation of CN radical in interstellar ice analogs. Solid H-2 acts as a hydrogenation agent, reacting with CN radicals to form HCN.