A systematic method that quantitatively assesses property prediction u
ncertainty (imprecision) on optimal molecular design problems is intro
duced. Property - structure relations are described with specific nonl
inear functionalities based on group contribution methods. Property pr
ediction uncertainty is explicitly quantified by using multivariate pr
obability density distributions to model the likelihood of different r
ealizations of the group contribution parameters. Assuming stability o
f these probability distributions, a novel approach is introduced for
transforming the original nonlinear stochastic formulation into a dete
rministic MINLP problem with linear binary and convex continuous parts
with separability. The resulting convex MINLP formulation is solved t
o global optimality for molecular design problems involving many uncer
tain group contribution parameters. Results indicate the computational
tractability of the method and the profound effect that property pred
iction uncertainty may have in optimal molecular design. Specifically,
trade-off curves between performance objectives, probabilities of mee
ting the objectives, and chances of satisfying design specifications o
ffer a concise and systematic way to guide optimal molecular design in
the face of property prediction uncertainty.