Professor Emeritus, Physics and Astronomy; Professor Emeritus, Chemistry
The Materials Theory Group at NU is dedicated to the development and application of theoretical tools useful for analysis of real materials. "Real materials" are solids and molecules of interest in technology, commerce, medicine and science; as such they posses surfaces, defects, and microstructure that can be processed to meet performance goals.
Such materials often have important structure on more than one time- and distance-scale; as a result hybrid methods that are optimized for each scale are attractive. The Group works with first principles methods, such as Density Functional Theory (DFT), to discover equilibrium configurations and electronic structures of rather small samples of up to a few hundred atoms. The resulting data are fed into semiclassical methods where time- and temperature-dependent properties involving thousands to millions of atoms can be traced. The interatomic potentials essential to semiclassical simulation are derived from iterative optimization of parameters, using both first principles data and experimental information. Molecular Dynamics (MD), Monte-Carlo sampling (MC), Kinetic Monte Carlo (KMC) process-tracking, and Lattice Monte Carlo (LMC) thermodynamic modeling form the main arsenal of simulation tools. Outputs of simulations, such as a relaxed surface structure with adsorbed molecules, are fed back into DFT algorithms for further predictive modeling.
Current Projects with a Strong Applied Physics Component
- Advanced Oxide-Based Fuel Cell Materials: Cooler, Lighter, Stronger, Cheaper
- Catalytic Behavior of Metal-doped Oxide Surfaces: Reducing Pollution, Creating Fuels
- Lattice and Electronic Properties of Actinide Compounds: Nuclear Fuel Cycles and Waste
- Bioceramics: Materials for Bone and Tooth Implants and Reconstruction; Remediation of Heavy Metal Poisoning
"Radial-template approach for accurate density representation in computational quantum theory," Lj. Miljacic and D.E. Ellis, J. Comp. Chem. 31, 1486 (2010).
"UTa2O(S2)3Cl6: A ribbon structure containing a heterobimetallic 5d-5f M3 cluster," D.M. Wells, G.H. Chan, D.E. Ellis, and J.A. Ibers, J. Sol. Sta.Chem. 183, 285 (2010).
"Local Electronic and Magnetic Structure of Mixed Ferrite Multilayer Materials," D.M. Wells, J. Cheng, D.E. Ellis, and B.W. Wessels, Phys. Rev. B81, 174422 (2010).
"First-principles Investigations of Ti-substituted Hydroxyapatite Electronic Structure," S. Yin and D.E. Ellis, Phys. Chem. Chem. Phys. 12, 156 (2010).
"A Combined Quantum Theoretical Methodology to Study Zn Substitution in (001) Hydrated Hydroxyapatite Surfaces," M. Matos, J. Terra, and D.E. Ellis, J.Phys: Cond. Matt. 22, 145502 (2010).