© Published under licence by IOP Publishing Ltd. We report on photoionization studies of Xe.CF4 and Kr.CF4 van-der-Waals (vdW) clusters produced in a supersonic expansion and detected using synchrotron radiation and photoelectron- photoion coincidence techniques. Complementary ab initio calculations of the potential energy surfaces for the ground state and the first ionized state are performed and show generally good agreement with the experimental results. In particular, the calculation reveals a change in the equilibrium configuration from face to vertex geometry upon ionization. This observation is fully in line with the lineshapes of the Xe.CF4 and Kr.CF4 clusters in the photoelectron spectra.