F + OH reactive collisions on new excited A″3 and A′3 potential-energy surfaces

Abstract

Global three-dimensional adiabatic potential-energy surfaces for the excited 2(3)A" and 1(3)A' triplet states of OHF are obtained to study the F(2P)+OH(2pi)-->O(3P)+HF(1sigma+) reaction. Highly accurate ab initio calculations are obtained for the two excited electronic states and fitted to analytical functions with small deviations. The reaction dynamics is studied using a wave-packet treatment within a centrifugal sudden approach, which is justified by the linear transition state of the two electronic states studied. The reaction efficiency presents a marked preference for perpendicular orientation of the initial relative velocity vector and the angular momentum of the OH reagent, consistent in the body-fixed frame used with an initial collinear geometry which facilitates the access to the transition state. It is also found that the reaction cross section presents a rather high threshold so that, in an adiabatic picture, the two excited triplet states do not contribute to the rate constant at room temperature. Thus, only the lowest triplet state leads to reaction under these conditions and the simulated rate constants are too low as compared with the experimental ones. Such disagreement is likely to be due to nonadiabatic transitions occurring at the conical intersections near the transition state for this reaction.

An accurate study of the dynamics of the C+OH reaction on the second excited 14A″ potential energy surface

“…The astrophysical interest of reactions between free radicals has motivated an ample list of recent studies of collisions between open-shell atoms such as C( 3 P), [1][2][3][4][5][6][7] N( 4 S), [8][9][10] F( 2 P), [11][12][13][14] O( 3 P), [15][16][17][18] or S( 3 P) (Refs. 19 and 20) with the hydroxyl radical OH( 2 ).…”

Time‐dependent quantum study of H(2S) + FO(2Π) → OH(2Π) + F(2P) reaction on the 13A′ and 13A″ states

“…For this reason, Gomez-Carrasco et al 12,13 further reported several coupled diabatic potential energy surfaces (1 3 A , 2 3 A , and 1 3 A ) and extended their previous dynamics study of the F(…”

“…12 The simple J-Shifting method is used to compute the reaction probabilities for J > 0. The total reactive cross-sections are calculated by summing the partial probabilities over all J values and the initial state selected rate constants are calculated by Boltzmann averaging the integral cross sections.…”

Vector correlations in the F + HO → HF + O reaction and its isotopic variant

“…In 2000, Kornweitz et al have reported the threecenter semi-empirical potential energy surfaces of the F + HX and F + OH reactions [3]. Gómez-Carrasco et al also investigated the potential surfaces for this OHF reactive system, and they successfully constructed a series of PESs (potential energy surfaces) for the different electronic states of the system [4][5][6]. Based on these PESs and employed the one for the 3 A" electronic state, Gonzalez-Sanchez et al [7], Zhao et al [8,9], and Han et al [10] reported the stereodynamics characters of the OHF system.…”