Graphical and tabulated data and the associated bibliography are presented for cross sections for elastic, excitation, and ionization collisions of N+, N+2, N, and N2with N2and for Ar+and Ar with Ar for laboratory energies from 0.1 eV to 10 keV. Where appropriate, drift velocities and reaction or excitation coefficients are calculated from the cross sections and recommended for use in analyses of swarm experiments and electrical discharges. In the case of N+in N2, cross sections for momentum transfer, charge transfer, electronic excitation, and electron production are recommended. Drift velocity calculations predict runaway for N+in N2for electric field to gas density ratiosE/ngreater than 4.3×103Td, where 1 Td (townsend)=10−21V m2. For N+2in N2, the cross sections include those for N+and N+3formation, electronic excitation, and electron production. Drift velocities and average cross sections are calculated forE/n≥500 Td. In the case of N in N2, only cross sections for momentum transfer are recommended. For N2in N2, cross sections for momentum transfer, electronic excitation, and electron production are recommended. Collisions of electronically excited states with N2are not included. For Ar+in Ar, cross sections for charge transfer, electronic excitation, and electron production are recommended. For Ar in Ar, cross sections for momentum transfer, electronic excitation, and electron production are recommended.