Diabatic excited states of the (HeH2)+ molecular ion for the charge exchange-excitation reaction: He+ + H2 → HeH+ + H∗

Sidis, V.

doi:10.1016/0301-0104(96)00060-2

Cited by 13 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Approximated theoretical models were also employed (Dhuicq et al, 1996) for explaining observed cross sections above 9 eV, when excited H * ( n = 2) was produced. Finally, quantum infinite-order-sudden cross sections were calculated (Martínez et al, 2000) for He + +H 2 → He+H * ( n ≥ 2)+H + at E coll ≥ 10 eV, using the accurate diabatic representation of Aguado et al (1993) and six more approximated diabatic electronic states (Sidis, 1996).…”

Section: Introductionmentioning

confidence: 99%

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

2019

View full text Add to dashboard Cite

We present the non-adiabatic, conical-intersection quantum dynamics of the title collision where reactants and products are in the ground electronic states. Initial-state-resolved reaction probabilities, total integral cross sections, and rate constants of two H 2 vibrational states, v 0 = 0 and 1, in the ground rotational state ( j 0 = 0) are obtained at collision energies E coll ≤ 3 eV. We employ the lowest two excited diabatic electronic states of and their electronic coupling, a coupled-channel time-dependent real wavepacket method, and a flux analysis. Both probabilities and cross sections present a few groups of resonances at low E coll , whose amplitudes decrease with the energy, due to an ion-induced dipole interaction in the entrance channel. At higher E coll , reaction probabilities and cross sections increase monotonically up to 3 eV, remaining however quite small. When H 2 is in the v 0 = 1 state, the reactivity increases by ~2 orders of magnitude at the lowest energies and by ~1 order at the highest ones. Initial-state resolved rate constants at room temperature are equal to 1.74 × 10 −14 and to 1.98 × 10 −12 cm 3 s −1 at v 0 = 0 and 1, respectively. Test calculations for H 2 at j 0 = 1 show that the probabilities can be enhanced by a factor of ~1/3, that is ortho- H 2 seems ~4 times more reactive than para- H 2 .

show abstract

Section: Introductionmentioning

confidence: 99%

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

2019

View full text Add to dashboard Cite

show abstract

“…Besides its relevance in the hydrogen plasma chemistry, process is a fundamental pathway for the formation of molecular hydrogen cation in the early Universe. ,− Concerning these last models, however, to include correctly this process in the master equation, rate constants in a collision energy range of 4 orders of magnitude should be inserted, because of the rapid adiabatic expansion (and the consequent cooling) of the Universe in its first ages after the atomic recombination era. In this range of temperatures, of course, different processes (e.g., nonadiabatic and collision-induced dynamics) of the HeH 2 + system can be relevant, so that a pure quantum mechanical approach, although extended to cover a large range of temperatures, has important limitations.…”

Section: Introductionmentioning

confidence: 99%

“…9,56−58 Concerning these last models, however, to include correctly this process in the master equation, rate constants in a collision energy range of 4 orders of magnitude should be inserted, because of the rapid adiabatic expansion (and the consequent cooling) of the Universe in its first ages after the atomic recombination era. In this range of temperatures, of course, different processes (e.g., nonadiabatic 59 and collision-induced dynamics) of the HeH 2 + system can be relevant, so that a pure quantum mechanical approach, although extended to cover a large range of temperatures, has important limitations. The present work is organized as follows: in section 2 some details of the chemical system and of the employed reaction dynamical methods are given; in section 3 the results are shown and reported in different subsections.…”

Section: Introductionmentioning

confidence: 99%

Complementarity between Quantum and Classical Mechanics in Chemical Modeling. The H + HeH⁺ → H₂⁺ + He Reaction: A Rigourous Test for Reaction Dynamics Methods

2015

View full text Add to dashboard Cite

In this work we present a dynamical study of the H + HeH+ → H2+ + He reaction in a collision energy range from 0.1 meV to 10 eV, suitable to be used in applicative models. The paper extends and complements a recent work [ Phys. Chem. Chem. Phys. 2014, 16, 11662] devoted to the characterization of the reactivity from the ultracold regime up to the three-body dissociation breakup. In particular, the accuracy of the quasi-classical trajectory method below the three-body dissociation threshold has been assessed by a detailed comparison with previous calculations performed with different reaction dynamics methods, whereas the reliability of the results in the high energy range has been checked by a direct comparison with the available experimental data. Integral cross sections for several HeH+ roto-vibrational states have been analyzed and used to understand the extent of quantum effects in the reaction dynamics. By using the quasi-classical trajectory method and quantum mechanical close coupling data, respectively, in the high and low collision energy ranges, we obtain highly accurate thermal rate costants until 15 000 K including all (178) the roto-vibrational bound and quasi-bound states of HeH+. The role of the collision-induced dissociation is also discussed and explicitly calculated for the ground roto-vibrational state of HeH+.

show abstract

“…Compared with equation (25), reaction (32) has greater interest: as discussed in [87], it occurs on an excited adiabatic potential energy surface of the triatomic system He ‡ ‡ H 2 ; at close distances, the atom± biatom interaction becomes strongly repulsive and the adiabatic surface has avoided crossings with a sequence of upper excited, quasi-Rydberg, states, posing severe problems for the de® nition of the diabatic potentials [57] able to explain the so called R ¤ reaction and the presence of electronically excited hydrogen atoms among the reaction products.…”

Section: Manifolds Of Diabatic Statesmentioning

confidence: 99%

Numerical techniques for the evaluation of non-adiabatic interactions and the generation of quasi-diabatic potential energy surfaces using configuration interaction methods

et al. 2000

View full text Add to dashboard Cite

CI techniques, based on nearly complete expansions over determinants for subsets of molecular orbitals and electrons, have been extended to evaluate, by ® nite di erences, nonadiabatic interactions arising from the nuclear kinetic energy operator. A functional of the non-adiabatic interactions is de® ned and, from the minimum condition of the functional, a simple expression is obtained for the transformation matrix to the quasi-diabatic basis. Two di erent schemes for the minimization of the functional, with and without constraints to the form of the transformation matrix, have been compared. Simple tests are presented to verify the numerical accuracy of the non-adiabatic interactions and to compare the two schemes for the minimization of the functional.

show abstract

Diabatic excited states of the (HeH2)+ molecular ion for the charge exchange-excitation reaction: He+ + H2 → HeH+ + H∗

Cited by 13 publications

References 24 publications

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

Complementarity between Quantum and Classical Mechanics in Chemical Modeling. The H + HeH⁺ → H₂⁺ + He Reaction: A Rigourous Test for Reaction Dynamics Methods

Numerical techniques for the evaluation of non-adiabatic interactions and the generation of quasi-diabatic potential energy surfaces using configuration interaction methods

Contact Info

Product

Resources

About

Diabatic excited states of the (HeH2)+ molecular ion for the charge exchange-excitation reaction: He+ + H2 → HeH+ + H∗

Cited by 13 publications

References 24 publications

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

Complementarity between Quantum and Classical Mechanics in Chemical Modeling. The H + HeH+ → H2+ + He Reaction: A Rigourous Test for Reaction Dynamics Methods

Numerical techniques for the evaluation of non-adiabatic interactions and the generation of quasi-diabatic potential energy surfaces using configuration interaction methods

Contact Info

Product

Resources

About

Complementarity between Quantum and Classical Mechanics in Chemical Modeling. The H + HeH⁺ → H₂⁺ + He Reaction: A Rigourous Test for Reaction Dynamics Methods