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Results for D + H2

We implemented Eq. (18) and used it, along with real wave packet propagation, to calculate total reaction probabilities for the three-dimensional D + H $_2(v_I=j_I=0) \longrightarrow$ DH + H reaction with total angular momentum J=0. The Liu-Siegbahn-Truhlar-Horowitz (LSTH) potential energy surface[17,18,19] was used. For comparison, we also present results from a real wave packet propagation combined with the asymptotic product analysis method[12].

The asymptotic product analysis results are based on the same grids and parameters as given in Ref. [12]. Thus, we outline only a few key aspects. Product (DH+H) Jacobi coordinates were employed for the real wave packet propagation, with 80 evenly spaced grid points from 0.15 a.u. to 12.0 a.u. in the R and r coordinates, and 50 Legendre polynomials ( $j_F=0,1,\ldots,49$) for $\cos\gamma$. Product analysis was performed at $R_\infty$ = 6.5 a.u. The results, labeled ``G-BK'' in Table 1 are simply the sum of all the possible state-to-state probabilities. For the flux calculations we implemented Eq. (18). These calculations were carried out in reactant (D+H2) Jacobi coordinates Ra, ra and $\cos
\gamma_a$. 80 evenly spaced grid points in Ra from 0.15 to 12 a.u. were employed. It suffices for the diatomic coordinate ra to employ 59 grid points 0.5 to 9.5 a.u. The $\cos
\gamma_a$ degree of freedom was expanded in 25 even (jI = 0,2,...,48) Legendre polynomials. The flux was calculated at the surface defined by ra = 6.0 a.u. (The reactant coordinate propagation, owing to the diatomic symmetry and to the smaller ra grid is significantly more efficient.) The total reaction probability denoted by ``flux'' in Table 1 represents the result. 1000 iterations of Eq. (14) suffices to converge the reaction probabilities. Table 1 shows that the agreement between the results from the flux and earlier G-BK approaches is excellent.


next up previous
Next: Conclusions Up: Flux analysis for calculating Previous: Flux analysis of real
Anthony J. H. M. Meijer
1998-06-19