Maximilian Amsler, will present seminar. Professor Cyrus Umrigar, host. 

Seminar Title:  In silico materials design: porous high-pressure intermetallics and rattling Heusler compounds

Abstract: S With increasing computational resources and novel, efficient algorithms, it has become possible to predict materials solely based on computer simulations prior to their experimental synthesis. A key challenge in materials prediction is to find the correct arrangement of atoms in a crystal lattice, the crystal structure, which fundamentally defines the physical, chemical and mechanical properties of a compound. Reliable crystal structure prediction methods are especially valuable to study materials at conditions where experimental structure determination is impossible or very difficult, for example at extreme pressures. In this talk, I will present a crystal structure prediction algorithm based on the minima hopping method (MHM), and examples of its successful application in conjunction with density functional theory calculations. On one hand, I will focus on high-pressure materials discovery, particularly in alloy systems that are known to exhibit strong immiscibility at ambient conditions. Elements that commonly don’t bond at all can form compounds once a sufficiently high pressure is applied, resulting in intermetallics that exhibit superconducting or exotic, low-dimensional structural properties with potential use in metal-ion batteries. On the other hand, I will show how structure prediction can be combined with high-throughput and “big-data” efforts to screen a large chemical space for new energy materials. In particular, I will present our recent discovery of ultralow thermal conductivity in a new class of Heusler semiconductors for thermoelectric applications.

Poster available.