A fast generation and test algorithm is applied within a new approach for designing branched molecules with physical properties and molecular constraints. Computer-aided product design requires the generation of feasible compounds and the prediction of mixture and pure-component properties by group contribution methods. A desirable property of the molecular design procedure is the chemical stability/feasibility of the generated chemical structures. On the basis of the electronegativity of the group attachments, a new characterization of group combination properties and the corresponding feasibility criteria for computer-aided generation of branched structures are presented. A synthesis procedure and a strategy for reducing the size of the c...