Classical trajectory calculations of ion-permanent+induced dipole capture processes are performed over very wide ranges of conditions. The results are represented in a simple, two-parametric analytical form of high precision. The transition from adiabatic to nonadiabatic dynamics is expressed in terms of the Massey parameter. In the adiabatic range, perfect agreement (better than 0.4%) of the derived thermal capture rate constants from classical trajectories and results from accurate statistical adiabatic channel (SACM) calculations is obtained.