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Kokoouline V, Alijah A, Tyuterev V. Lifetimes and decay mechanisms of isotopically substituted ozone above the dissociation threshold: matching quantum and classical dynamics. Phys Chem Chem Phys 2024; 26:4614-4628. [PMID: 38251711 DOI: 10.1039/d3cp04286c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
Energies and lifetimes of vibrational resonances were computed for 18O-enriched isotopologue 50O3 = {16O16O18O and 16O18O16O} of the ozone molecule using hyperspherical coordinates and the method of complex absorbing potential. Various types of scattering resonances were identified, including roaming OO-O rotational states, the series corresponding to continuation of bound vibrational resonances of highly excited bending or symmetric stretching vibrational modes. Such a series become metastable above the dissociation limit. The coupling between the vibrationally excited O2 fragment and rotational roaming gives rise to Feshbach type resonances in ozone. Different paths for the formation and decay of symmetric 16O18O16O and asymmetric species 16O16O18O were also identified. The symmetry properties of the total rovibronic wave functions of the 18O-enriched isotopologues are discussed in the context of allowed dissociation channels.
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Affiliation(s)
| | - Alexander Alijah
- Groupe de Spectrometrie Moléculaire et Atmospherique, UMR CNRS 7331, University of Reims Champagne-Ardenne, Reims Cedex 2, F-51687, France
| | - Vladimir Tyuterev
- Laboratory of Molecular Quantum Mechanics and Radiative transfer, Tomsk State University, Tomsk, Russia
- Laboratory of Theoretical Spectroscopy, V.E. Zuev Institute of Atmospheric Optics, Russian Academy of Sciences, Tomsk, 634055, Russia
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Kalugina YN, Egorov O, van der Avoird A. Ab initio study of the O 3-N 2 complex: Potential energy surface and rovibrational states. J Chem Phys 2021; 155:054308. [PMID: 34364361 DOI: 10.1063/5.0061749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The formation and destruction of O3 within the Chapman cycle occurs as a result of inelastic collisions with a third body. Since N2 is the most abundant atmospheric molecule, it can be considered as the most typical candidate when modeling energy-transfer dynamics. We report a new ab initio potential energy surface (PES) of the O3-N2 van der Waals complex. The interaction energies were calculated using the explicitly correlated single- and double-excitation coupled cluster method with a perturbative treatment of triple excitations [CCSD(T)-F12a] with the augmented correlation-consistent triple-zeta aug-cc-pVTZ basis set. The five-dimensional PES was analytically represented by an expansion in spherical harmonics up to eighth order inclusive. Along with the global minimum of the complex (De = 348.88 cm-1), with N2 being perpendicular to the O3 plane, six stable configurations were found with a smaller binding energy. This PES was employed to calculate the bound states of the O3-N2 complex with both ortho- and para-N2 for total angular momentum J = 0 and 1, as well as dipole transition probabilities. The nature of the bound states of the O3-oN2 and O3-pN2 species is discussed based on their rovibrational wave functions.
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Affiliation(s)
- Yulia N Kalugina
- Laboratory of Quantum Mechanics of Molecules and Radiative Processes, Tomsk State University 36, Lenin Ave., Tomsk 634050, Russia
| | - Oleg Egorov
- Laboratory of Quantum Mechanics of Molecules and Radiative Processes, Tomsk State University 36, Lenin Ave., Tomsk 634050, Russia
| | - Ad van der Avoird
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Bop CT, Quintas-Sánchez E, Sur S, Robin M, Lique F, Dawes R. Inelastic scattering in isotopologues of O 2-Ar: the effects of mass, symmetry, and density of states. Phys Chem Chem Phys 2021; 23:5945-5955. [PMID: 33666616 DOI: 10.1039/d1cp00326g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The two species considered here, O2 (oxygen molecule) and Ar (argon-atom), are both abundant components of Earth's atmosphere and hence familiar collision partners in this medium. O2 is quite reactive and extensively involved in atmospheric chemistry, including Chapman's cycle of the formation and destruction of ozone; while Ar, like N2, typically plays the nevertheless crucial role of inert collider. Inert species can provide stabilization to metastable encounter-complexes through the energy transfer associated with inelastic collisions. The interplay of collision frequency and energy transfer efficiency, with state lifetimes and species concentrations, contributes to the rich and varied chemistry and dynamics found in diverse environments ranging from planetary atmospheres to the interstellar and circumstellar media. The nature and density of bound and resonance states, coupled electronic states, symmetry, and nuclear spin-statistics can all play a role. Here, we systematically investigate some of those factors by looking at the O2-Ar system, comparing rigorous quantum-scattering calculations for the 16O16O-40Ar, 18O16O-40Ar, and 18O18O-40Ar isotope combinations. A new accurate potential energy surface was constructed for this purpose holding the O2 bond distance at its vibrationally averaged distance.
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Affiliation(s)
- Cheikh T Bop
- Laboratoire Ondes et Milieux Complexes, UMR 6294, Centre National de la Recherche Scientifique-Universite du Havre, F-76063 Le Havre, France. and Universite du Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | | | - Sangeeta Sur
- Missouri University of Science and Technology, Rolla, MO 65409-0010, USA.
| | - Mathurin Robin
- Laboratoire Ondes et Milieux Complexes, UMR 6294, Centre National de la Recherche Scientifique-Universite du Havre, F-76063 Le Havre, France.
| | - François Lique
- Laboratoire Ondes et Milieux Complexes, UMR 6294, Centre National de la Recherche Scientifique-Universite du Havre, F-76063 Le Havre, France. and Universite du Rennes, CNRS, IPR (Institut de Physique de Rennes) - UMR 6251, F-35000 Rennes, France
| | - Richard Dawes
- Missouri University of Science and Technology, Rolla, MO 65409-0010, USA.
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Quintas-Sánchez E, Dawes R. Spectroscopy and Scattering Studies Using Interpolated Ab Initio Potentials. Annu Rev Phys Chem 2021; 72:399-421. [PMID: 33503385 DOI: 10.1146/annurev-physchem-090519-051837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Born-Oppenheimer potential energy surface (PES) has come a long way since its introduction in the 1920s, both conceptually and in predictive power for practical applications. Nevertheless, nearly 100 years later-despite astonishing advances in computational power-the state-of-the-art first-principles prediction of observables related to spectroscopy and scattering dynamics is surprisingly limited. For example, the water dimer, (H2O)2, with only six nuclei and 20 electrons, still presents a formidable challenge for full-dimensional variational calculations of bound states and is considered out of reach for rigorous scattering calculations. The extremely poor scaling of the most rigorous quantum methods is fundamental; however, recent progress in development of approximate methodologies has opened the door to fairly routine high-quality predictions, unthinkable 20 years ago. In this review, in relation to the workflow of spectroscopy and/or scattering studies, we summarize progress and challenges in the component areas of electronic structure calculations, PES fitting, and quantum dynamical calculations.
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Affiliation(s)
- Ernesto Quintas-Sánchez
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA;
| | - Richard Dawes
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, USA;
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Mandal B, Semenov A, Babikov D. Adiabatic Trajectory Approximation within the Framework of Mixed Quantum/Classical Theory. J Phys Chem A 2020; 124:9877-9888. [DOI: 10.1021/acs.jpca.0c07547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bikramaditya Mandal
- Chemistry Department, Wehr Chemistry Building, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Alexander Semenov
- Chemistry Department, Wehr Chemistry Building, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Dmitri Babikov
- Chemistry Department, Wehr Chemistry Building, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
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Ben Khalifa M, Quintas-Sánchez E, Dawes R, Hammami K, Wiesenfeld L. Rotational quenching of an interstellar gas thermometer: CH 3CNHe collisions. Phys Chem Chem Phys 2020; 22:17494-17502. [PMID: 32716451 DOI: 10.1039/d0cp02985h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Among all the molecular species found in the interstellar medium, molecules with threefold symmetry axes play a special role, as their rotational spectroscopy allows them to act as practical gas thermometers. Methyl-cyanide (CH3CN) is the second most abundant of those (after ammonia). We compute in this paper the collisional dynamics of methyl-cyanide in collision with helium, for both the A- and the E-symmetries of CH3CN. The potential energy surface is determined using the CCSD(T)-F12b formalism and fit with convenient analytic functions. We compute the rotationally inelastic cross sections for all levels up to 510 cm-1 of collision energy, employing at low energy exact Coupled Channels methods, and at higher energies, approximate Coupled States methods. For temperatures from 7 K up to 300 K, rates of quenching are computed and most are found to differ from those reported earlier (up to a factor of a thousand), calling for a possible reexamination of the temperatures assigned to low density gasses.
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Affiliation(s)
- M Ben Khalifa
- Laboratoire Aimé-Cotton, CNRS and Université Paris-Saclay, Orsay, France. and Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Université Tunis El-Manar, Tunis, Tunisie.
| | - E Quintas-Sánchez
- Missouri University of Science and Technology, Rolla, MO 65409-0010, USA
| | - R Dawes
- Missouri University of Science and Technology, Rolla, MO 65409-0010, USA
| | - K Hammami
- Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Université Tunis El-Manar, Tunis, Tunisie.
| | - L Wiesenfeld
- Laboratoire Aimé-Cotton, CNRS and Université Paris-Saclay, Orsay, France.
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