Energy levels, transition frequencies and Einstein A coefficients were taken from JPL. The collisional rates are taken from Green (1995) and were calculated for temperatures in the range from 25 to 125 K including energy levels up to 62 cm^-1 for collisions with He. This set of collisional rate coefficients, multiplied by 1.4 to represent collisions with H₂, was extrapolated to include energy levels up to 250 cm^-1 and for a range of temperatures from 10 to 375 K. For details on the extrapolation see Schöier al. (2005).

• References
  Green,S. 1995, ApJS, 100, 213
  Schöier, F.L, van der Tak, F.F.S., van Dishoeck, E.F., Black, J.H. 2005, A&A 432, 369