Research Abstracts Online
January 2010 - March 2011
University of Minnesota Twin Cities
College of Science and Engineering
of Chemical Engineering and Materials Science
PI: Renata M. Wentzcovitch, Fellow
Theory of Materials at High Pressures and Temperatures
The Wentzcovitch group’s research is in the area of materials theory and computations, with a very interdisciplinary flavor. The primary focus is on minerals and planetary materials. These are structurally and electronically complex materials whose study involves large-scale density functional (DFT) based computations of magnetic, thermodynamics, and thermal elastic properties. Mineral physics is one of the three pillars of geophysics, the other two being seismology and geodynamics. Therefore, this group investigates properties needed to interpret seismic data or used as input for geodynamics simulations. The single most important materials property in geophysics is elasticity and the researchers have been advancing these calculations for almost two decades. Other contemporary problems involve spin-state change in deep mantle minerals and their geophysical consequences and the storage capacity for water in the mantle, i.e., the water cycle. The researchers investigate properties of hydrous and nominally anhydrous minerals, attempting to clarify processes and signature of water in rocks of the deep mantle. They also investigate properties of planetary materials in the multi-Mbar pressure regime. Very little is known about materials properties at the conditions typical of the interior of giant planets.
This group also conducts research in spintronic materials, since their structural and electronic properties have a similar degree of complexity to minerals. The focus of this research is to understand properties of strongly correlated oxides, especially those controlled by temperature, such as polarization and spin crossovers, just like it happens with oxide and silicate minerals in the deep earth mantle.
From the computational viewpoint, these studies must sample a wide range of physical parameters such as pressure, temperature, compositions, atomic configurations, strains, etc. These are high-throughput computations requiring thousands of small- to medium-scale first-principles parallel calculations, each one using hundreds to thousands of cores. These studies are well suited for hexascale platforms, but equally well for distributed environments since these runs are decoupled at various stages of these calculations. Therefore, this research also advances software for distributed computing on the Internet.
Pedro da Silveira, Graduate Student
Han Hsu, Research Associate
Neal R. Kelly, Undergraduate Student
Maribel Nunes-Valdez, Graduate Student
Koichiro Umemoto, Faculty Collaborator
Yuichiro Yamagami, Research Associate
Yonggang Yu, Research Associate