The molecular designing of materials and devices

Arthur von Hippel, a pioneer in the emergence of modern materials science, had a great goal: "the molecular designing of materials and devices." In this article, I describe how computational materials theory has evolved over the last half century, helping to transform that goal from dream to reality. I start with two great puzzles of the 1950s: why band theory and the nearly free electron picture work. These were resolved by Landau's quasiparticle theory and by pseudopotential theory, respectively. Together with the creation and development of density functional theory, Key methodological advances, and the rapid evolution of computer hardware and software, these two Insights have resulted in the achievement of the quantitative prediction of the structures and properties of complex materials. Bandgap engineering and design of multilayer multifunctional materials are given as examples of "molecular design.".