Potential energy surface and wave packet calculations on the Li+HF→LiF+H reaction

Abstract

Adiabatic global potential energy surfaces, for singlet and triplet states of AЈ and AЉ symmetries, were computed for an extensive grid for a total of 8469 conformations of H 3 ϩ system at full configuration interaction ab initio level and using an extended basis set that has also been optimized for excited states. An accurate ͑root-mean-square error lower than 20 cm Ϫ1 ) global fit to the ground-state potential is obtained using a diatomics-in-molecules approach corrected by several symmetrized three-body terms with a total of 96 linear parameters and 3 nonlinear parameters. This produces an accurate global potential which represents all aspects of ground-state H 3 ϩ including the absolute minimum, the avoided crossing and dissociation limits, satisfying the correct symmetry properties of the system. The rovibrational eigenstates have been calculated up to total angular momentum Jϭ20 using hyperspherical coordinates with symmetry adapted basis functions. The infrared spectra thus reproduced is within 1 cm Ϫ1 with respect to the experimental values for several transitions.

Full dimensional potential energy surface for the ground state of $\mathbf {H_4^+}$H4+ system based on triatomic-in-molecules formalism

“…48-51, and applied to a wide variety of triatomic systems. [52][53][54] In this case, to account for the permutation invariance, the four-body terms are expressed as linear combinations of symmetry adapted functions as 42,50,51 …”

Quantum stereodynamics of the Li+HF(v,j) reactive collision for different initial states of the reagent

“…It is particularly interesting the determination of the role of the transition state on the reaction dynamics, mainly for energies close to the threshold, and the M ϩHX systems present a wide variety of situations, the reactions being endothermic, exothermic or thermoneutral depending on the nature of the metal atom ͑M͒ and of the hydrogen halide molecule ͑HX͒, and on the initial excitation of the reactants. Nowadays, there is an increasing number of theoretical works on these systems [15][16][17][18][19][20] due to the development of the methodology to describe the reaction dynamics of three atoms systems and to the appearance of accurate global potential energy surfaces ͑GPES͒ for some of these systems like LiϩHF 16,19 or NaϩHF. [20][21][22] Another source of valuable information is the reaction dynamics dependence on the relative velocity vectors between reactants and products and on the angular momenta involved in the process.…”

Quasi‐classical trajectory stereodynamics study of the Li + HF(v = 0, j = 0) → LiF + H reaction

“…The potential energy surface used here is constructed by Aguado et al [13,15] As mentioned previously, this AP2-PES is an improved one of the original PES of the same authors, fitted from a set of the calculated ab initio data covering most of the relevant interaction region [15]. It corresponds to the ground state of the LiFH system and can be written as [13] follows,…”