Collisional rate coefficients are taken from the litterature and include collisions with: hydrogen (Launay and Roueff 1977), electrons (Wilson & Bell 2002), and molecular hydrogen (Flower and Launay 1977).

• References
  Flower, D. R. & Launay, J. M. 1977, J. Phys. B., 10, 3673
  Launay, J.M. & Roueff, E. 1977, J.Phys.B, 10, 879
  Wilson, N. J. & Bell, K. L. 2002, MNRAS, 337, 1027