Abstract: An analysis is presented that allows calculating properties of primary solid solutions in ionic crystals. These properties are expressed in terms of properties of the undoped host material and the impurity. One can calculate the solubilities of the impurities with a knowledge of the concentration of the ‘corresponding native defects’, the standard chemical potential of the materials involved and the shear modulus of the host material. The changes in concentrations of ionic point defects as well as electron/hole concentrations due to doping are also calculated. In order to do so one has to know the concentrations of the native point defects in the undoped host material and the concentration of the dopant. It is shown that in a native p-type semiconductor (e.g. Cu2O) donors are mainly self-compensated by ionic defects, while acceptors are compensated significantly by holes.