Total per-channel cross sections for five ionization (red curves; O K shell in purple) and five excitation (blue curves) channels in (a) amorphous and (b) hexagonal ice after relativistic corrections. Note: the plotted cross sections are molecular cross sections computed for an ice density of 1 g cm⁻³. In Geant4-IcyMoons, bulk density effects are accounted for by scaling interaction rates at runtime using the molecular number density.