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Updated: Aug 8, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Theoretical characterization of the gas-phase O(3)HO hydrogen-bonded complex
Alex Mansergas1, Josep M Anglada
1Theoretical and Computational Chemistry Group, Departament de Química Orgànica Biològica, Institut d'Investigacions Químiques i Ambientals de Barcelona, IIQAB-CSIC, c/Jordi Girona 18, 08034 Barcelona, Spain.
Abstract:
We report a theoretical study on two gas-phase hydrogen-bonded complexes formed between ozone and hydroxyl radical that have relevance to atmospheric chemistry. This study was carried out by using CASSCF, CASPT2, QCISD, and CCSD(T) theoretical approaches in conjunction with the 6-311+G(2df,2p) and aug-cc-pVTZ basis sets. Both complexes have a planar structure and differ from each other in the orientation of the electronic density of the unpaired electron associated with the HO radical moiety. Our calculations predict their stabilities to be 0.87 and 0.67 kcal mol(-1), respectively, at 0 K and show the importance of anharmonic effects in computing the red shift of the HO stretch originating from the hydrogen-bonding interaction. We also report two transition states involving the movement of the HO moiety on the potential energy surfaces of these hydrogen-bonded complexes.
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