Theoretical Studies of Dissociative Recombination
We are currently investigating the dissociative recombination (DR) of electrons with molecular
ions such as N2H+ and C3H+3 . Both these ions exist in the interstellar medium, and accurate DR rate constants are needed for astrophysical models. Elaborate electronic structure calculations of potential surfaces for eā + N2H+ ā N2 + H have been carried out in the linear geometry [D. Talbi, Chem. Phys.
332, 289 (2007)]. Additional work is necessary to determine the autoionization width Ī, which is essential for a dynamics calculation. We are using the block diagonalization method to determine both diabatic potential curves and Ī; the status of the calculations will be presented at the conference. In addition, preliminary work on the C3H+3 molecular ion has investigated the normal modes of the motion. We expect that energy flow into and out of the vibration of a single CH bond may influence
the overall DR dynamics, and we account for this effect using an appropriate quantum mechanical wave function for the initial state.