Rotationally inelastic collisions of electrons with H2 and N2 molecules: Converged space-frame calculations at low energies

The quantum treatment of the collisional excitation of rotations in H 2 and N2 gases as test molecules is carried out within a space-fixed frame of reference by solving the multichannel close-coupled equations using an approach newly developed in our group, i.e. the modified variable phase approximation (MVPA). The interaction potentials contain the static, exchange and correlation-polarisation contributions and are obtained via a local, multipolar expansion formulation from ab initio data. The results are compared with existing experiments and produce numerically converged rotationally inelastic cross-sections obtained from an exact molecular-frame treatment of the problem.