Abstract: The computerized method, software, and product of this invention implements a process for computationally designing proteins and/or associated molecular targets with desired quantitative stability/flexibility relationships (QSFR). QSFR is an innovative, high dimensional metric calculated using an improved Distance Constraint Model (DCM). This invention includes three distinct aspects: (i.) utilizing QSFR in computational molecular design of protein sequences, or variations of molecular structures, to have specific stability and flexibility relationships deemed important for biochemical function for specified thermodynamic and solvent conditions; (ii.) utilizing QSFR to optimize thermodynamic and/or solvent conditions necessary for a specified molecular system to exhibit protein function characteristics, such as improved catalytic efficiency; and (iii.) utilizing QSFR to computationally screen or design small molecules and/or design its putative receptor so as to exhibit a desired affect on protein function.