Collisional rate coefficients are taken from the literature and include collisions with H (Barinovs et al 2005), e (Wilson & Bell 2002), and H₂ (Lique et al. 2013).

The standard datafile only includes the fine structure transition while a second file includes the principal ultraviolet transitions.

The rates for para-H₂ assume thermalized rotational populations in hydrogen and include both H₂(J=0) and H₂(J=2) as collision partners (Wiesenfeld & Goldsmith 2014).