I present a microscopic cluster model which is used in two ways, to compute transfer cross sections in light or medium-mass nuclei. In the first approach, the cross section is directly determined from a fully microscopic model, known as the Resonating Group Method (RGM). The wave functions are obtained from cluster wave functions, defined in the shell model. Then the coupling between the entrance and exit channels provides the scattering matrices, and the cross sections. This approach is well adapted to low energies (typically around or below the Coulomb barrier), and to low level-densities. It is essentially used in nuclear astrophysics, where the relevant cross sections are too small to be measured in the laboratory.
At higher energies, many open channels and resonances are present. In that case, a fully microscopic model is not applicable. A standard optical potential simulates the absorption due to the open channels. This technique is referred to as the DWBA method and is essentially used to determine the properties (spin, spectroscopic factor) of the residual nucleus. In that case, the RGM permits to calculate the overlap integral of the residual nucleus. Recent examples on 16C(d,p)17C and 6He(d,n)7Li will be presented.