When I was a teenager and was interested in chemistry 30 years ago, the question that bothers me all the time if it is possible to predict physical characteristics such as color, phase diagrams, and - yes - smell from chemical composition and structure. Tried to do that with pen and paper, but did not get much farther that acids smell acidic and alkali smell alkaline, and salts largely do not smell unless they easily dissociate. I quickly realized that the most interesting part of this problem is in organic compounds but that was well beyond my reach. Thinking about it now I am wondering about the choice of “variables”. To me it looks like we are trying to describe complex smells in terms of combination of other probably also complex smells. Is it the right base? If I were researching that I would try to find the bases - either chemical compounds with the simplest structure, like benzol, or compounds that trigger the minimal number of receptors and different and disjoint sets of receptors at that. Is there any research in that area?