Modelling Vibrational Dissociation of [H2–HCO]+. Issue 33 (5th September 2019)

• Record Type: Journal Article
• Authors: Kraus, Peter; Alznauer, H. Tobias; Frank, Irmgard
• Is Part Of: ChemistrySelect. Volume 4:Issue 33(2019)
• Page Start: 9794
• Page End: 9801
• Publication Date: 2019-09-05
• Subjects: Car-Parrinello -- formyl cation -- hydrogen complex -- Molecular dynamics -- non-covalent interactions; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201902216
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: The [H2 –HCO] + complex is likely to be one of the most important complexes in interstellar space, as it is a complex of the most abundant interstellar species. In the current work, we investigate the interaction energy and potential surface of the complex using a range of computational methods. The dynamics of the complex are investigated by incorporating an external time‐dependent field into Car‐Parrinello molecular dynamics (CPMD) and inducing a vibrationally activated dissociation. This excitation method is compared to a normal‐mode excitation from the equilibrium structure. The results agree well with the available experimental data: an excitation to the first vibrationally‐excited state of either of the high‐frequency HCO + modes (ν2, ν3 ) causes a dissociation of the complex on picosecond timescales. Abstract : As H2 and CO are the most abundant species in the interstellar space, the [H2 –HCO] + complex is likely one of the most abundant van der Waals complexes. Therefore we investigate the potential energy surface and the dissociation dynamics of the complex and its deuterated isotopologue, using a combination of ab initio methods. The complex dissociates from the first vibrationally excited state, and it can easily isomerise into an out‐of‐plane conformation, in line with previous experimental observations.