The H3+ rovibrational spectrum revisited with a global electronic potential energy surface

Velilla, Luis; Lepetit, Bruno; Aguado, Alfredo; Beswick, J. A.; Paniagua, Miguel

doi:10.1063/1.2973629

Cited by 95 publications

(126 citation statements)

References 63 publications

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“…We have improved our previous study 24 by employing a larger (and converged) nuclear statistics, and investigated the effect of the accuracy of the H + 3 PES parametrization on dynamical results by using the pioneering parametrization of Giese and Gentry, 27 V GG , and the most recent one of Velilla et al, 28 V VLA . We have found that inelastic cross sections are indeed sensitive to the accuracy of the PES from low (few eV) to intermediate (100 eV) impact energies.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, V GG has been originally designed to describe H + +H 2 collisions without rearrangement; in the case of nuclear exchange and dissociation processes, ρ and R are redefined during the collision. This is not necessary when using the PES of Velilla et al, 28 V VLA . This PES is constructed on DIM grounds, but all long-range terms are included in the diagonal elements of the DIM matrix, yielding a global potential function symmetric under any permutation of the three identical nuclei.…”

Section: Nuclear Evolutionmentioning

confidence: 99%

“…27 In this respect, Ichihara et al 4 have noted that, in the framework of TSH calculations, H + +H 2 inelastic cross sections are indeed sensitive, within 20%, to the accuracy of the PES employed. Accordingly, we present in this contribution CT-DIM calculations that employ the analytical parametrization of Velilla et al 28 (V VLA ), based on large-scale ab initio calculations. We gauge the relation between the accuracy of the PES and calculated cross sections by direct comparison of both nuclear and electron dynamics using V GG and V VLA .…”

Section: Introductionmentioning

confidence: 99%

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Influence of nuclear exchange on nonadiabatic electron processes in H$^+$++H$_2$2 collisions

Errea

Illescas

Macías

et al. 2010

The Journal of Chemical Physics

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H + +H 2 collisions are studied by means of a semiclassical approach that explicitly accounts for nuclear rearrangement channels in nonadiabatic electron processes. A set of classical trajectories is used to describe the nuclear motion, while the electronic degrees of freedom are treated quantum mechanically in terms of a three-state expansion of the collision wavefunction. We describe electron capture and vibrational excitation, which can also involve nuclear exchange and dissociation, in the E = 2-1000 eV impact energy range. We compare dynamical results obtained with two parametrizations of the potential energy surface of H + 3 ground electronic state. Total cross sections for E > 10 eV agree with previous results using a vibronic close-coupling expansion, and with experimental data for E < 10 eV. Additionally, some prototypical features of both nuclear and electron dynamics at low E are discussed.

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Section: Discussionmentioning

confidence: 99%

Section: Nuclear Evolutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of nuclear exchange on nonadiabatic electron processes in H$^+$++H$_2$2 collisions

Errea

Illescas

Macías

et al. 2010

The Journal of Chemical Physics

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“…The PES by Velilla et al [35], which includes the LR interactions in the functional form, satisfies the first requirement. The dominant contributions involve the charge quadrupole, ∝ − R −3 , and the charge-induced dipole, ∝−R −4 , interactions.…”

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confidence: 98%

Beyond universality: Parametrizing ultracold complex-mediated reactions using statistical assumptions

et al. 2015

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We have calculated accurate quantum reactive and elastic cross sections for the prototypical barrierless reaction D + + H 2 (v = 0, j = 0) using a modified hyperspherical scattering method. The considered kinetic energy ranges from the ultracold to the Langevin regimes. A reaction rate coefficient practically constant in no less than eight orders of magnitude is obtained. The availability of accurate results for this system allows one to test the quantum theory by Jachymski et al. [K. Jachymski, M. Krych, P. S. Julienne, and Z. Idziaszek, Phys. Rev. Lett. 110, 213202 (2013)] in a nonuniversal case. The short-range reaction probability is rationalized using statistical model assumptions and related to a statistical factor. This provides a means to estimate one of the parameters that characterizes ultracold processes from first principles. The increasing availability of cold and ultracold samples of atoms and molecules has sprung great interest in chemical reactions at very low temperatures [1][2][3][4][5]. Although new experimental approaches [5] appear highly promising, advances in the field are hampered by technical problems in producing most molecules at low temperatures and high enough densities. In contrast to neutral species, ions can be easily trapped and cooled. The technology of Coulomb crystals in radiofrequency ion traps [6] and the possibility of combining them with traps for neutrals or with slow molecular beams [7,8] promise great progress in the analysis of ion-neutral reactions in the near future.Theoretical simulations employing standard ab initio approaches are not feasible for most of the systems thus far considered. For heavy systems (more convenient experimentally) there are no potential energy surfaces (PESs) accurate enough to describe processes near thresholds. Additionally, most of exact dynamical treatments face insurmountable problems in such regimes. However, in contrast to short-range (SR) chemical interactions, those occurring at long range (LR) can be more easily calculated. Moreover, theoretical approaches based only on the knowledge of the LR part of the PES have been able to describe recent experimental findings nearly quantitatively [1,9]. Indeed, processes at very low collision energies favor LR interactions, leading to the idea of universality in extreme cases [10]: the result of the collision depends exclusively on the LR behavior and not on the details of the PES. In this regard, recently proposed LR parametrization procedures [9,[11][12][13] Fitting experimental data, these models are able to predict nonmeasured values providing some insight into the underlying interactions. In particular, the approach by Jachymski et al., based on multichannel quantum-defect theory (MQDT), provides analytical expressions which can be easily compared with experimental data [9,14,15]. The model has been recently applied to a variety of systems [9,16,17]. In particular, for the Penning ionization of Ar by He( 3 S) [5], the rate coefficients have been fitted in a wide range of collision ener...

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“…New statistical calculations are also performed in order to test the possible statistical behavior of the H þ þ H 2 reaction. First, accurate three-dimensional quantum dynamics calculations have been performed on a recently published ab initio PES [12] that is rigorously symmetric under any permutation of the three identical atoms. It presents a deep well (4.6 eV relative to the H þ þ H 2 asymptote) and no barrier in the entrance channel.…”

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confidence: 99%

Ortho−ParaH2Conversion by Proton Exchange at Low Temperature: An Acc

et al. 2011

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We report extensive, accurate fully quantum, time-independent calculations of cross sections at low collision energies, and rate coefficients at low temperatures for thewhich is of key importance in astrophysics. This conversion process appears to be very efficient and dominant at low temperature, with a rate coefficient of 4:15 Â 10 À10 cm 3 molecule À1 s À1 at 10 K. The quantum mechanical results are also compared with statistical quantum predictions and the reaction is found to be statistical in the low temperature regime (T < 100 K).

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The H3+ rovibrational spectrum revisited with a global electronic potential energy surface

Cited by 95 publications

References 63 publications

Influence of nuclear exchange on nonadiabatic electron processes in H$^+$++H$_2$2 collisions

Influence of nuclear exchange on nonadiabatic electron processes in H$^+$++H$_2$2 collisions

Beyond universality: Parametrizing ultracold complex-mediated reactions using statistical assumptions

Ortho−ParaH2Conversion by Proton Exchange at Low Temperature: An Acc

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