1. COMPUTATIONAL PHYSICS Aniket Bhattacharya 1 GS + 1UGS Archana Dubey - Abdelkader Kara 1 UGS Talat Rahman 7 GS + 1 REU + 5.2 PostDocs Patrick Schelling 2 GS + 1UGS + 3 REU Sergey Stolbov 1GS ~ 30 papers in the last 12 months Research: multi-tools to study physical and chemical properties of materials at different time and length scales. Development: new tools to extend the accuracy and speed of simulations to larger length and time scales

2. Abdelkader KARA RESEARCH Organic MaterialsSilicene Pentacene/Cu(110) Adsorption energy: 1.49 eV Diffusion barrier: 150 meV Sexithiophene on Ag(110) Experiment Pentacene on p(2x1)O /Cu(110) [0 0 1] [1 1 0] Charge transfer Diffusion barrier: 66 meV akara@mail.ucf.edu www.physics.ucf.edu/~kkaraakara@mail.ucf.edu Nano-Ribbons: Si/Ag(110) Confinement Side view Interface states : theory and

3. Abdelkader KARA DEVELOPMENT Self-Learning Kinetic Monte Carlo In collaboration with Rahman’s group On Lattice Recognition Gain in Speed and Precision Go over all atoms and determine all processes determine all processes which are possible. which are possible. Γ (i) = Γ o (i) exp(-ΔE (i) /k B T ) get two random numbers r 1, r 2 from [0,1[ Do process “k”, i.e. move one atom (randomly chosen) adjust the clock: 1/R Calculate R = ΣΓ (i) and find process “k” from the data base: Σ k Γ (i) > r 1 R > Σ k-1 Γ (i) If novel Configuration occurs: occurs: Calculate∆E yes no Data base Start End Off Lattice Recognition Experiment SL-KMC simulation PREFACTORS Concerted Motion akara@mail.ucf.edu www.physics.ucf.edu/~kkaraakara@mail.ucf.edu

4. Aim: Understanding of proteins and enzymes at functional levels. Procedure: Hartree-Fock- Cluster procedure implemented by the Roothaan variational approach. The model system to simulate deoxy hemoglobin consists of a heme unit with imidazole of the proximal histidine attached to the Fe atom on the heme unit through one of the two N in the imidazole, namely the apex N ε in the figure. Peripheral carbons of the pyrroles in the heme unit are terminated by H atoms. Fe atom is rather internal in the central region of the heme unit, and the adjustments made in the peripheral regions of the heme are not expected to influence the electron distribution significantly in the neighborhood of the 57m Fe nucleus. Dr. Archana Dubey

5. Patrick K. Schelling, University of Central Florida Multiscale simulation of mass and heat transport NSF-DMR 0809015NSF-REU 0755256 Multiscale simulation of laser ablation Nanoscale thermal transport Complex oxides and geophysics Interfacial thermal transport and phonon dynamics Scattering simulation/theory Transport in nanocrystalline materials Effect of discrete phonon spectra Size-dependence of interfacial resistance Atomistic models with excited electrons Electron-phonon scattering Combined phonon/electron transport Oxides for thermal barrier coatings Point-defect scattering, disorder Transport in MgSiO 3 up to p=120GPa Cross-sectional view of simulated Si nanowires Phonon scattering at Si grain boundary

6. First principles studies of stability and reactivity of electro-catalysts for low-temperature fuel cells Sergey Stolbov, Associate Professor, Physics Dept. UCF Stability: Search for new materials to replace unacceptably expensive Pt in electrodes of low-temperature fuel cells (FC) is an important and challenging problem for electro-catalysis. Promising electro-catalysts such as Ru nanoparticles with the Pt (Pt/Ru) and Se (Se/Ru) sub-monolayer coverage have a complex geometric structure that makes their stability an issue of concern. We apply the density functional theory (DFT) based computational approach to reveal key characteristics of stability of these materials. We find that Pt atoms tend to join into large 2D islands by making Pt-Pt and Pt-Ru covalent bonds, while Se atoms charged by electron transfer form the surface repeal and hence prefer stay apart from each other on the substrate. Island formation energy per/atom of Pt (right panel) and Se (left panel) as a function of the island size Work in progress: 1.In collaboration with M. Alcantara Ortigoza and T. S. Rahman we are studying electronic structure and energetics of layered Ru/Pt and Ru/Pt/Ru structures to explain character of growth of such structures observed in experimental works by R.J. Behm and co-workers ( Vacuum 84, 13 (2010), Surf. Sci. 603, 2556 (2009)). 2.With graduate student S. Zuluaga we begun studying geometric and electronic structures of Se-Ru nano-clusters. M. Alcantara Ortigoza, S. Stolbov and T. S. Rahman, PRB, 78, 195417 2008 Pt/Ru Se/Ru S. Stolbov, in preparation