Velocity-dependent charge-exchange cross sections used in the hybrid model for single charge transfer of H⁺ and He²⁺ ions with H₂O. The points represent the datasets (observations or model), the solid and dashed lines the polynomial fit of degree 4 made in each case. Coefficients for the fits are given in Table 2. The model results of Mada et al. (2007) are adjusted to match the laboratory results of Lindsay et al. (1997) at 1.5 keV impact energy (~ 979 km s^-1). The fit is performed after the adjustment.