A method used to guess at (determine) the three-dimensional structure of a receptor binding site extrapolating from the known structure of the molecule binding to it. This approach can be carried out because of the complementary shape of the receptor and the binding molecule. Functionally, the researcher projects the (guessed-at) properties of the receptor ligands into a mathematical model in which the profile of the receptor is predicted by complementariness (to known chemical molecular structures). The receptor mapping process requires repetitive refinement of the mathematical model to fit properties continually being discovered via the use/interaction of chemical reagents bearing the known molecular structures.