Comparison of two datasets of rate coefficients for HCNH⁺ induced by collisions with p-H₂(j₂ = 0). The x-axis represents the first dataset, computed using the “exact” CC method (Bop & Lique 2023), while the y-axis represents the second dataset, calculated in this work using the CS approximation. The dashed lines indicate an agreement region within a factor of 2.0. Different colors represent their weighted mean error factors (WMEF) which are defined in Eq. (1).