ROTIONS: a program for the calculation of rotational excitation cross sections in electron-molecular ion collisions. ROTIONS is a program for the calculation of cross sections for rotational excitation of linear molecular ions by electron impact. The cross sections can be obtained from input T-matrices and from the Coulomb-Born approximation for dipole (Δj=1) and quadrupole (Δj=2) transitions. The Coulomb-Born results can be used to augment the low partial-wave T-matrices to an effectively infinite number of partial waves. (Source: http://cpc.cs.qub.ac.uk/summaries/)