Promiscuity underlies the concept of drug repurposing . A promiscuous drug (i.e. ligand) implies that it is structurally and chemically complementary to several receptor, while a promiscuous receptor implies that several ligands possess high similarity. Limiting our ability to exploit ligand similarity for repurposing are the difficulties to experimentally elucidate or theoretically predict 3D conformations and their electrostatic profiles. This difficulty arises from the dynamic nature of molecules and their complex multidimensional potential energy surface . Affirming this is the fact that only a fraction of the 1634 approved small-molecule drugs have a single 3D conformation resolved.