Materials are increasingly being applied in devices that derive their function from small-scale, and even nanometer-scale, features. Examples include advanced battery materials and quantum wires proposed for use in next generation opto-electronics. Features on these scales are subject to profound changes over time due to the thermally induced motion of atoms. The focus of this project is to develop the computational tools referred to as "meta-codes," that are required for predicting the way these features evolve with time. These meta-codes allow researchers to consider these problems by integrating knowledge obtained from the smallest scales, on which electrons control atomic interactions, to the largest scales, on which elastic interactions drive features to form or dissolve with time. Thus, the aim of the project is to build an automated, top-down way of working that naturally integrates tools from quantum mechanics, statistical physics and continuum elasticity for the computational design of materials.
The broader impact of this work arises from the development of an approach that integrates chemistry, physics and mechanics, and that can be used to refine our understanding of how a wide variety of materials systems evolve when there exist large spatial variations in composition and stress. The intellectual impact comes both from an increased understanding of how to develop meta- codes to undertake multi-scale modeling and from a deeper understanding of the energy storage and electronic materials studied with these novel tools. The projects includes active participation of students at the undergraduate, graduate and postdoctoral level, and incorporates a series of outreach activities that leverage those ongoing in the involved institutions.
This award is part of the Cyber-Enabled Discovery and Innovation program, and the recipients are Professors Michael Falk of Johns Hopkins University, Krishnakumar Garikipati and Anton Van der Ven of the University of Michigan Ann Arbor.
In this project we have developed the mathematical models and computer code to model certain types of transformations in materials ranging from structural materials to battery materials. These phenomena are characterized by changes in chemistry as well as the microscopic structure (the crystal structure) of the materials. The have previously been treated with a not quite correct description of the elastici deformations. When the elasticity is properly modelled, it introduces certain mathematical challenges, which result in inconsistent mathematical and physical results. These inconsistencies are eliminated by the treatment provided here. A new class of numerical methods also was needed for the computations. A wholly new paradigm of computer modelling was developed to enable this project. In this paradigm, models at atomic scales were used to inform those at larger, macroscopic scales, with the computer codes for each of these scales directly communicating with each other. These are the meta-codes described in the title of the project. This is the intellectual merit of this project. The broader impacts lie in the fact the meta-code paradigm can and is being applied to other problems in materials science, including oxidation, and even to biophysics. Additionally, we have trained a post-doctoral scholar who is now on the research faculty at University of Michigan.
