Prof. Vladan Stevanovic delivered an A3MD Distinguished Seminar entitled: “Toward Accelerated Discovery and Design of Metastable Materials”
Metastable materials, including both crystalline and amorphous systems, are invaluable in our daily lives. Classic examples include diamond, amorphous SiO2 (glass) or solid chocolate. However, despite the relevance of metastable materials and despite a rather extensive knowledge of the phenomenology of metastability, our ability to rationally discover and design metastable forms of matter is rather limited. In this talk I will present our recent attempts to resolving some of the issues hindering rational discovery and design of metastable phases with the particular focus on covalent and partially ionic (semiconducting/insulating) systems. More specifically, I will discuss the experimental realizability (synthesizability) of metastable crystalline phases (polymorphs) in connection to specific features of the potential energy surface leading to an effective methodology to identifying realizable metastable states. Next, I will talk about our efforts in developing computational methods to enable large-scale assessment of the kinetics of polymorphic transformations (i.e., polymorph lifetimes). , These are predicated on the novel solution to the problem of finding an optimal atom-to-atom mapping between infinitely periodic systems. Lastly, an alternative description of covalent and ionic glassy solids as statistical ensembles of crystalline local minima on the potential energy surface will be discussed, opening the door to fully predictive approaches to modeling glasses without the need for experimental inputs. In all of these areas our recent works offer quantitative predictions of relevant properties, which, in turn, can help construct more rational and reliable searches for useful metastable materials. This work is supported by the NSF-DMR Career program.