Upper panel: influence of the hadronic interaction model on the computation of the Venusian ion-pair production rates. A comparison between the QGSP_BIC, QGSP_ BIC_HP, FTFP_ BERT and FTFP_BERT_HP models for primary protons between 1 MeV nuc⁻¹ and 1 TeV nuc⁻¹ is shown. In comparison, the proton-induced ionization rates by Nordheim et al. (2015) are displayed (dashed line). Middle panel: influence of the energy range on the GCR-induced ion-pair production based on the FTFP_ BERT_HP model for primary protons between 1 MeV–100 GeV, 1 MeV–1 TeV and 1 MeV–10 TeV. The results by Plainaki et al. (2016) are given in light blue. Lower panel: influence of primary protons of selected energy bins on the ion pair production rates at altitudes below 60 km (for further information see Sect. 4.1.3).