MSE Seminar: Chen Huang, Los Alamos National Laboratory

Potential-Functional Embedding Theory: An Effective and Rigorous Way to Perform Multiphysics Quantum Mechanics Simulations for Materials and Molecules Abstract: Accurate and detailed electronic structures are prerequisites for our understanding and prediction of properties of molecules and materials. Ideally, we just need to solve the Schrödinger equation in quantum mechanics which has been introduced for over 80 years. Unfortunately, the many-body nature of the Schrödinger equation makes itself extremely difficult to solve. Theories of varying levels of accuracy exist in the literature to approximately solve the Schrödinger equation. Very accurate methods, such as the configuration interaction method, often have a computational cost that scales exponentially with system sizes. Efficient methods, such as the Kohn-Sham density functional theory, often have large errors that are difficult to predict. All these difficulties severely limit the predictive power of computer simulations. A novel way to obtain accurate electronic properties in large-scale materials is quantum mechanics embedding theory, in which the key regions in materials are solved using highly accurate methods, with the unimportant regions solved by less accurate methods. In this talk, I will present our recent breakthrough in quantum mechanics embedding theory: the potential-functional embedding theory, [1,2] which provides a unified framework to perform multiphysics simulations of materials and molecules in a seamless and first-principle manner. I will also present the application of our embedding theory to two long-term puzzles related to surface catalysis and corrosion: (a) the true bonding nature between carbon monoxide and copper surface [2], and (b) the counterintuitive process of the oxidation of aluminum surface. [3] References: [1] C. Huang and E.A. Carter, J. Chem. Phys., 135, 194104 (2011). [2] C. Huang, M. Pavone, and E. A. Carter, J. Chem. Phys., 134, 154110 (2011). [3] F. Libisch, C. Huang, P. Liao, M. Pavone, and E.A. Carter, Phys. Rev. Lett., 109, 198303 (2012). Biography: Dr. Chen Huang is currently a postdoctoral research associate in the Theoretical Division at Los Alamos National Laboratory. He received his Ph.D. in physics from Princeton University in 2011, and B.Sc. from Tsinghua University, Beijing, China. His research focuses on developing novel theoretical methods to solve challenging electronic structure and kinetic problems in materials and molecules. He is the main inventor of the potential-functional embedding theory, which provides an effective and rigorous way to perform multiphysics quantum mechanics simulations for complex materials and molecules. With this embedding theory, he and coworkers have successfully unveiled the complicated process of the oxidation of metal surface, which has puzzled the scientific and industrial communities for decades. Another research area of Dr. Huang is long-time simulation methodology. At Los Alamos, he is actively developing accelerated molecular dynamics (AMD), which is promising to bridge the timescale gap between experiments and simulations. His work on AMD provides an effective way to predict striking kinetic processes in materials and would greatly advance computer-aided rational design of materials. Faculty Host: David Bishop Student Host: Yang Yu