Comparison of the HCNH⁺ cross sections for selected total energies. We note that σ_{J = 0 − 5} is the sum of partial cross sections over total angular momenta up to J = 5. The stars depict the impact of including j₂ = 0 − 2 in comparison to the constraint of the H₂ rotational basis to j₂ = 0, while the empty circles estimate the influence of a more exhaustive H₂ rotational manifold (j₂ = 0 − 4) with respect to j₂ = 0 − 2. The dashed diagonal lines delimit an agreement region of a factor of 1.5.