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Jani pour H, Noorbala MR, Namazian M. Intermolecular potential energy surfaces of NeH3+ and ArH3+ systems using ab initio methods. COMPUT THEOR CHEM 2023. [DOI: 10.1016/j.comptc.2023.114050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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2
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Calculation of the intermolecular potential energy surfaces of $${\mathbf{H}\mathbf{e}\mathbf{H}}_{3}^{+}$$ by means of ab initio methods. Theor Chem Acc 2022. [DOI: 10.1007/s00214-022-02905-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Merkt F, Höveler K, Deiglmayr J. Reactions of H 2, HD, and D 2 with H 2+, HD +, and D 2+: Product-Channel Branching Ratios and Simple Models. J Phys Chem Lett 2022; 13:864-871. [PMID: 35045261 PMCID: PMC8802320 DOI: 10.1021/acs.jpclett.1c03374] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
We present measurements of the product-channel branching ratios of the reactions (i) HD+ + HD forming H2D+ + D (38.1(30)%) and HD2+ + H (61.9(30)%), (ii) HD+ + D2 forming HD2+ + D (61.4(35)%) and D3+ + H (38.6(35)%), and (iii) D2+ + HD forming HD2++ D (60.5(20)%) and D3+ + H (39.5(20)%) at collision energies Ecoll near zero, i.e., below kB × 1 K. These branching ratios are compared with branching ratios predicted using three simple models: a combinatorial model (M1), a model (M2) describing the reactions as H-, H+-, D-, and D+-transfer processes, and a statistical model (M3) that relates the reaction rate coefficients to the translational and rovibrational state densities of the HnD3-n+ + H/D (n = 0, 1, 2 or 3) product channels. The experimental data are incompatible with the predictions of models M1 and M2 and reveal that the branching ratios exhibit clear correlations with the product state densities.
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Affiliation(s)
- Frédéric Merkt
- Laboratorium für
Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
| | - Katharina Höveler
- Laboratorium für
Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland
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Aguado A, Roncero O, Sanz-Sanz C. Three states global fittings with improved long range: singlet and triplet states of H. Phys Chem Chem Phys 2021; 23:7735-7747. [PMID: 32930276 DOI: 10.1039/d0cp04100a] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Full dimensional analytical fits of the coupled potential energy surfaces for the three lower singlet and triplet adiabatic states of H are developed, providing analytic derivatives and non-adiabatic coupling matrix elements. The fits are highly accurate and include an improved description of the long range interactions, including new terms for the description of the long range in the diatomic fits and the atom-diatom dissociation channels. The fits are based on the DIM formalism including three body terms in Hamiltonian matrix elements, each of them obeying S2 permutational symmetry, where the positive charge is placed in either of the three hydrogen atoms, but the full system obeys S3 permutational symmetry, invariant under all permutations of the nuclei. The ab initio points used in the fitting are obtained from a complete basis set extrapolation, made for all electronic states. Total root mean square errors of the fits are 27 and 12 cm-1, for the singlet and triplet states, respectively. The errors in the channels are lower than 2 cm-1 and 6 cm-1 for the H + H and H+ + H2 channels respectively. The new fits have been used to calculate the rovibrational bound states of the lowest singlet and lowest triplet states showing very good agreement with previous calculations in the literature.
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Affiliation(s)
- Alfredo Aguado
- Unidad Asociada UAM-CSIC, Departamento de Química Física Aplicada, Módulo 14, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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Sanz-Sanz C, Aguado A, Roncero O. Near-resonant effects in the quantum dynamics of the H + H 2 + → H 2 + H + charge transfer reaction and isotopic variants. J Chem Phys 2021; 154:104104. [PMID: 33722048 DOI: 10.1063/5.0044320] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The non-adiabatic quantum dynamics of the H + H2 + → H2 + H+ charge transfer reactions, and some isotopic variants, is studied with an accurate wave packet method. A recently developed 3 × 3 diabatic potential model is used, which is based on very accurate ab initio calculations and includes the long-range interactions for ground and excited states. It is found that for initial H2 +(v = 0), the quasi-degenerate H2(v' = 4) non-reactive charge transfer product is enhanced, producing an increase in the reaction probability and cross section. It becomes the dominant channel from collision energies above 0.2 eV, producing a ratio between v' = 4 and the rest of v's, which that increase up to 1 eV. The H + H2 + → H2 + + H exchange reaction channel is nearly negligible, while the reactive and non-reactive charge transfer reaction channels are of the same order, except that corresponding to H2(v' = 4), and the two charge transfer processes compete below 0.2 eV. This enhancement is expected to play an important vibrational and isotopic effect that needs to be evaluated. For the three proton case, the problem of the permutation symmetry is discussed when using reactant Jacobi coordinates.
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Affiliation(s)
- Cristina Sanz-Sanz
- Unidad Asociada UAM-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Alfredo Aguado
- Unidad Asociada UAM-CSIC, Departamento de Química Física Aplicada, Facultad de Ciencias M-14, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Octavio Roncero
- Instituto de Física Fundamental (IFF-CSIC), C.S.I.C., Serrano 123, 28006 Madrid, Spain
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Höveler K, Deiglmayr J, Agner JA, Schmutz H, Merkt F. The H 2+ + HD reaction at low collision energies: H 3+/H 2D + branching ratio and product-kinetic-energy distributions. Phys Chem Chem Phys 2021; 23:2676-2685. [PMID: 33480928 DOI: 10.1039/d0cp06107g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fully state-selected reactions between H2+ molecules in the X+ 2Σg+(v+ = 0, N+ = 0) state and HD molecules in the X 1Σg+(v = 0, J = 0) state forming H3+ + D and H2D+ + H have been studied at collision energies Ecoll between 0 and kB·30 K with a resolution of about 75 mK at the lowest energies. H2 molecules in a supersonic beam were prepared in Rydberg-Stark states with principal quantum number n = 27 and merged with a supersonic beam of ground-state HD molecules using a curved surface-electrode Rydberg-Stark decelerator and deflector. The reaction between H2+ and HD was studied within the orbit of the Rydberg electron to avoid heating of the ions by stray electric fields. The reaction was observed for well-defined and adjustable time intervals, called reaction-observation windows, between two electric-field pulses. The first pulse swept all ions away from the reaction volume and its falling edge defined the beginning of the reaction-observation window. The second pulse extracted the product ions toward a charged-particle detector located at the end of a time-of-flight tube and its rising edge defined the end of the reaction-observation window. Monitoring and analysing the time-of-flight distributions of the H3+ and H2D+ products in dependence of the duration of the reaction-observation window enabled us to obtain information on the kinetic-energy distribution of the product ions and determine branching ratios of the H3+ + D and H2D+ + H reaction channels. The mean product-kinetic-energy release is 0.46(5) eV, representing 27(3)% of the available energy, and the H3+ + D product branching ratio is 0.225(20). The relative reaction rates correspond closely to Langevin capture rates down to the lowest energies probed experimentally (≈kB·50 mK).
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Affiliation(s)
- Katharina Höveler
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Johannes Deiglmayr
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Josef A Agner
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Hansjürg Schmutz
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - Frédéric Merkt
- Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland.
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McKemmish LK, Tennyson J. General mathematical formulation of scattering processes in atom-diatomic collisions in the RmatReact methodology. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180409. [PMID: 31378187 PMCID: PMC6710894 DOI: 10.1098/rsta.2018.0409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/26/2019] [Indexed: 06/10/2023]
Abstract
Accurately modelling cold and ultracold reactive collisions occurring over deep potential wells, such as [Formula: see text], requires the development of new theoretical and computational methodologies. One potentially useful framework is the R-matrix method adopted widely for electron-molecule collisions which has more recently been applied to non-reactive heavy-particle collisions such as Ar-Ar. The existing treatment of non-reactive elastic and inelastic scattering needs to be substantially extended to enable modelling of reactive collisions: this is the subject of this paper. Herein, we develop the general mathematical formulation for non-reactive elastic and inelastic scattering, photoassociation, photodissociation, charge exchange and reactive scattering using the R-matrix method. Of particular note is that the inner region, of central importance to calculable R-matrix methodologies, must be finite in all scattering coordinates rather than a single scattering coordinate as for non-reactive scattering. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Laura K. McKemmish
- School of Chemistry, University of New South Wales, Kensington, Sydney, NSW 2052, Australia
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
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Amaral PHR, Stanke M, Adamowicz L, Diniz LG, Mohallem JR, Alijah A. Non-adiabatic effects in the H 3+ spectrum. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180411. [PMID: 31378173 PMCID: PMC6710893 DOI: 10.1098/rsta.2018.0411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/03/2019] [Indexed: 06/10/2023]
Abstract
The effect of non-adiabatic coupling on the computed rovibrational energy levels amounts to about 2 cm-1 for H3+ and must be included in high-accuracy calculations. Different strategies to obtain the corresponding energy shifts are reviewed in the article. A promising way is to introduce effective vibrational reduced masses that depend on the nuclear configuration. A new empirical method that uses the stockholder atoms-in-molecules approach to this effect is presented and applied to H3+. Furthermore, a highly accurate potential energy surface for the D3+ isotopologue, which includes relativistic and leading quantum electrodynamic terms, is constructed and used to analyse the observed rovibrational frequencies for this molecule. Accurate band origins are obtained that improve existing data. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Paulo H. R. Amaral
- Department of Physics, Federal University of Minas Gerais, PO Box 702, 30123-970 Belo Horizonte, Minas Gerais, Brazil
| | - Monika Stanke
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudzia̧dzka 5, Toruń 87-100, Poland
| | - Ludwik Adamowicz
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ 85721, USA
| | | | - José R. Mohallem
- Department of Physics, Federal University of Minas Gerais, PO Box 702, 30123-970 Belo Horizonte, Minas Gerais, Brazil
| | - Alexander Alijah
- Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, University of Reims Champagne-Ardenne, 51687 Reims Cedex 2, France
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Tennyson J, Miller S. Hydrogen molecular ions: H 3+, H 5+ and beyond. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20180395. [PMID: 31378175 PMCID: PMC6710892 DOI: 10.1098/rsta.2018.0395] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/08/2019] [Indexed: 06/10/2023]
Abstract
Three decades after the spectroscopic detection of H3+ in space, the inspiring developments in physics, chemistry and astronomy of Hn+ (n = 3, 5, 7) systems, which led to this Royal Society Discussion Meeting, are reviewed, the present state of the art as represented by the meeting surveyed and future lines of research considered. This article is part of a discussion meeting issue 'Advances in hydrogen molecular ions: H3+, H5+ and beyond'.
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Affiliation(s)
- Jonathan Tennyson
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Steve Miller
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
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Császár AG, Hochlaf M. Special issue: atoms, molecules, and clusters in motion. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1602377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Attila G. Császár
- ELTE Eötvös Loránd University and MTA-ELTE Complex, Chemical Systems Research Group, Budapest, Hungary
| | - Majdi Hochlaf
- Université Paris-Est, Laboratoire Modélisation et, Simulation Multi Echelle, MSME UMR 8208 CNRS, Paris, France
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