Abstract
In continuation of a series of papers dealing with collisional (de)polarization data for the p- and d-states of singly ionized atoms, in this work we aim at providing new functions allowing the calculation of collisional (de)polarization rates of any f-state. To the best of our knowledge, there are no available (de)polarization data for thef-states of ions. We first extend our numerical code of collisions, and calculate the interaction potential between an ion in f-state and neutral hydrogen in its ground state. Elements of the interaction potential matrix are included in the coupled differential equations describing the evolution of the f-states. Collision probabilities are derived from these differential equations. Then, collisional rates are calculated for large ranges of values of the effective quantum number n* and the Unsold energy E-p. Sophisticated genetic programming (GP) methods are developed to fit the collisional data and generate analytical functions depending on n* and E-p. From the GP functions, we show how to obtain (de)polarization collisional rates of ions with hyperfine structure as well as complex ions. The accuracy of these functions is typically better than 10 per cent.