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Karman T, Besemer M, van der Avoird A, Groenenboom GC. Diabatic states, nonadiabatic coupling, and the counterpoise procedure for weakly interacting open-shell molecules. J Chem Phys 2018. [DOI: 10.1063/1.5013091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Tijs Karman
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Matthieu Besemer
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Ad van der Avoird
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Gerrit C. Groenenboom
- Theoretical Chemistry, Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Hinde RJ. Infrared-active spin-orbit transitions of halogen atom dopants in solid parahydrogen: the role of trapping site geometry. J Chem Phys 2013; 139:134305. [PMID: 24116566 DOI: 10.1063/1.4820529] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present theoretical calculations of the (2)P(1/2) ← (2)P(3/2) spin-orbit transition of Cl dopants embedded as substitutional impurities in solid parahydrogen (pH2) matrices. In the lower-energy (2)P(3/2) spin-orbit level, the Cl atom's electron density distribution is anisotropic, and slightly distorts the geometry of the atom's trapping site. This distortion leads to a blue shift in the spin-orbit transition energy; the blue shift is enhanced when we account for the large-amplitude zero point motions of the pH2 molecules surrounding the Cl dopant. We also show that the intensity of the transition depends on the geometry of the trapping site. In the gas phase, the (2)P(1/2) ← (2)P(3/2) atomic transition is electric dipole forbidden. However, when the Cl atom resides in trapping sites that mimic the hexagonal close packed morphology of pure solid pH2, the transition becomes electric dipole allowed through interaction-induced transition dipole moments. These transition dipole moments originate in the anisotropic electron density distribution of the lower-energy (2)P(3/2) spin-orbit level.
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Affiliation(s)
- Robert J Hinde
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600, USA
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Li J, Li Y, Guo H. Communication: Covalent nature of X⋯H2O (X = F, Cl, and Br) interactions. J Chem Phys 2013; 138:141102. [DOI: 10.1063/1.4801872] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Werschak A, Upadhyaya H, Volpp HR. Laser-induced fluorescence study of spin–orbit quenching of Cl(2P1/2) by H2, D2, and HD gases. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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5
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Abstract
We report fully-quantum, time-independent, scattering calculations for the spin-orbit quenching of Cl((2)P(1∕2)) by H(2) molecules at low and moderate temperature. Our calculations take into account chemical reaction channels. Cross sections are calculated for total energies up to 5000 cm(-1) which are used to determine, by thermal averaging, state-to-state rate coefficients at temperatures ranging from 50 to 500 K. Spin-orbit relaxation of chlorine is dominated by collisions with H(2) in the rotationally excited states j = 2 and j = 3. In the former case the near-resonant energy transfer is the primary relaxation mechanism. The inclusion of the reactive channel could lead differences compared to pure inelastic calculations. Good agreement is obtained with experimental relaxation measurements at room temperature.
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Affiliation(s)
- François Lique
- LOMC-UMR 6294, CNRS-Université du Havre, 25 rue Philippe Lebon, BP 540, 76058 Le Havre, France.
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González-Sánchez L, Aldegunde J, Jambrina PG, Aoiz FJ. Dynamical regimes on the Cl + H2 collisions: inelastic rainbow scattering. J Chem Phys 2011; 135:064301. [PMID: 21842927 DOI: 10.1063/1.3618721] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
While Cl + H(2) reactive collisions have been a subject of numerous experimental and theoretical studies, inelastic collisions leading to rotational energy transfer and/or vibrational excitation have been largely ignored. In this work, extensive quantum mechanical calculations covering the 0.5-1.5 eV total energy range and various initial rovibrational states have been carried out and used to perform a joint study of inelastic and reactive Cl + H(2) collisions. Quasiclassical trajectories calculations complement the quantum mechanical results. The analysis of the inelastic transition probabilities has revealed the existence of two distinct dynamical regimes that correlate with low and high impact parameters, b, and are neatly separated by glory scattering. It has been found that while high-b collisions are mainly responsible for |Δj| = 2 transitions which dominate the inelastic scattering, they are very inefficient in promoting higher |Δj| transitions. The effectiveness of this type of collision also drops with rotational excitation of H(2). In contrast, reactive scattering, that competes with |Δj| > 2 inelastic transitions, is exclusively caused by low-b collisions, and it is greatly favored when the reactants get rotationally excited. Previous studies focusing on the reactivity of the Cl + H(2) system established that the van der Waals well located in the entrance channel play a key role in determining the mechanism of the collisions. Our results prove this to be also a case for inelastic processes, where the origin of the double dynamical regime can be traced back to the influence exerted by this well that shapes the topology of the entrance channel of the Cl-H(2) system.
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Affiliation(s)
- L González-Sánchez
- Grupo de Dinámica Molecular, Departamento de Química Física, Facultad de Química, Universidad de Salamanca, 37008 Salamanca, Spain
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Alexander MH, Kłos J, Manolopoulos DE. Nonadiabatic effects in the photodetachment of ClH2−. J Chem Phys 2008; 128:084312. [DOI: 10.1063/1.2834690] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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8
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Abrahamsson E, Groenenboom GC, Krems RV. Spin-orbit relaxation of Cl(P1∕22) and F(P1∕22) in a gas of H2. J Chem Phys 2007; 126:184303. [PMID: 17508799 DOI: 10.1063/1.2732751] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The authors present quantum scattering calculations of rate coefficients for the spin-orbit relaxation of F(2P1/2) atoms in a gas of H2 molecules and Cl(2P1/2) atoms in a gas of H2 and D2 molecules. Their calculation of the thermally averaged rate coefficient for the electronic relaxation of chlorine in H2 agrees very well with an experimental measurement at room temperature. It is found that the spin-orbit relaxation of chlorine atoms in collisions with hydrogen molecules in the rotationally excited state j=2 is dominated by the near-resonant electronic-to-rotational energy transfer accompanied by rotational excitation of the molecules. The rate of the spin-orbit relaxation in collisions with D2 molecules increases to a great extent with the rotational excitation of the molecules. They have found that the H2/D2 isotope effect in the relaxation of Cl(2P1/2) is very sensitive to temperature due to the significant role of molecular rotations in the nonadiabatic transitions. Their calculation yields a rate ratio of 10 for the electronic relaxation in H2 and D2 at room temperature, in qualitative agreement with the experimental measurement of the isotope ratio of about 5. The isotope effect becomes less significant at higher temperatures.
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Affiliation(s)
- Erik Abrahamsson
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3 Canada
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Grinev TA, Tscherbul TV, Buchachenko AA, Cavalli S, Aquilanti V. Interactions of 2P Atoms with Closed-Shell Diatomic Molecules: Alternative Diabatic Representations for the Electronic Anisotropy. J Phys Chem A 2006; 110:5458-63. [PMID: 16623475 DOI: 10.1021/jp056143v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The matrices of electrostatic and spin-orbit Hamiltonians for the system of a 2P atom interacting with a closed shell diatomic molecule in uncoupled, coupled, and complex-valued representations for electronic diabatic basis functions are rederived, and the unitary transformations connecting them are given explicitly. The links to previous derivations are established and existing inconsistencies are identified and eliminated. It is proven that the block-diagonalization of a 6 x 6 matrix of the electronic Hamiltonian is a result of using the basis functions with well-defined properties with respect to time reversal. Consideration of time-reversal symmetry also enforces phase consistency relevant for applications to multisurface reactive scattering and photodetachment spectroscopy calculations, as well as for perspective studies of inelastic effects in cold and ultracold environments. These and further developments are briefly sketched.
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Affiliation(s)
- Timur A Grinev
- Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry, Moscow State University, 119992 Moscow, Russia
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Rode JE, Klos J, Rajchel L, Szczesniak MM, Chalasinski G, Buchachenko AA. Interactions in open-shell clusters: ab initio study of pre-reactive complex O(3P) + HCl. J Phys Chem A 2005; 109:11484-94. [PMID: 16354039 DOI: 10.1021/jp053419q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Van der Waals interactions between the ground-state triplet O(3P) atom and the closed-shell HCl molecule are investigated in the pre-reactive region. Three adiabatic (two of A'' symmetry and one of A' symmetry) and four non-relativistic diabatic potential energy surfaces are obtained by combining a restricted open-shell coupled cluster approach with the multireference configuration interaction method. The lower A'' adiabatic potential surface has a single minimum (D(e) = 589 cm(-1)) for a linear O...HCl configuration. The upper A'' potential has a weak (D(e) = 65 cm(-1)) minimum for a linear HCl...O configuration. The A' adiabatic potential has a weak (124 cm(-1)) T-shaped minimum. Adiabatic potentials intersect once in the O...HCl linear configuration and twice in the linear HCl...O geometry. The role of electrostatic interactions in shaping these potentials is discussed. The effects of spin-orbit coupling on this interaction are also investigated assuming a constant value of the SO parameter.
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Affiliation(s)
- Joanna E Rode
- Department of Chemistry, Oakland University, Rochester, Michigan 48309, USA
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Neumark DM. Probing the transition state with negative ion photodetachment: experiment and theory. Phys Chem Chem Phys 2005; 7:433-42. [DOI: 10.1039/b417886f] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Klos J, Szczesniak MM, Chalasinski * G. Paradigm pre-reactive van der Waals complexes: X–HX and X–H2(X = F, Cl, Br). INT REV PHYS CHEM 2004. [DOI: 10.1080/01442350500063634] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Buchachenko AA, Grinev TA, Kłos J, Bieske EJ, Szczȩśniak MM, Chałasiński G. Ab initio potential energy and dipole moment surfaces, infrared spectra, and vibrational predissociation dynamics of the 35Cl−⋯H2/D2 complexes. J Chem Phys 2003. [DOI: 10.1063/1.1626620] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Zeimen WB, Kłos J, Groenenboom GC, van der Avoird A. Diabatic intermolecular potentials and bound states of open-shell atom–molecule dimers: Application to the F([sup 2]P)–H[sub 2] complex. J Chem Phys 2003. [DOI: 10.1063/1.1562623] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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