Ab initio potential energy surface and quantum scattering studies of Li ⁺ with N <inf>2</inf> : comparison with experiments at Ec.m.=2.47eV and 3.64Â eV

Abstract: A new ground electronic state potential energy surface of Li ++ N 2 system is presented in the Jacobi scattering coordinates at MRCI level of accuracy employing the augmented correlation-consistent polarized valence quadrupole zeta (aug-cc-pVQZ) basis set. An analytic fit of the computed ab initio surface has also been obtained. The surface has a global minimum for the collinear geometry at the internuclear distance of N 2, r= 2.078 a0, and the distance between Li + and N 2, R= 4.96 a0. Quantum dynamics studies have been performed within the vibrational close coupling-rotational infinite-order sudden approximation at Ec. m.= 3.64 eV, and the collision attributes have been analyzed. The computed total differential cross-sections are found in quantitative agreement with those available from the experiments at Ec.m.=3.64eV. The other dynamic attributes such as angle dependent opacities and integral cross-sections are also reported. Preliminary rigid-rotor and vibrational–rotational coupled-state calculations at Ec.m.=2.47eV also support the experimental observation that the system exhibits a large number of rotational excitations in the vibrational manifold v= 0. Graphical Abstract : SYNOPSIS Quantum scattering dynamics studies for vibrational-rotational excitations of N2 upon collisions of Li+ have been carried out on a newly computed ground electronic state potential energy surface and the computed collision attributes are compared with those available from the experiments at collision energies, Ec. m.= 2.47 eV and 3.64 eV [Figure not available: see fulltext.].