Hello, A yearly allocation for the LCRC cluster has been requested with the following updated information: Submitter/PI: Julius Jellinek Project Name: Comp_Nanocatalysis Division: CSE Project title: Theoretical/Computational Studies of the Fundamentals of One-Component and Alloy Metal Based Nanocatalysis Relevant to Alternative Sources of Energy Associated funding: BES/DOE Other Systems: NERSC, ~400000 core-hours Science: The central objective of this project is to characterize the chemical reactivity and catalytic functionality of one-component and alloy metal nanoparticles as a function of their size, structure and composition, as well as the material and morphology of their supports. The reactions considered will be those of relevance to alternative sources of energy. Project description: The subject of this project is structural, electronic, and chemical reactivity properties of one-component and alloy metal nanocatalysts, both gas phase and deposited on oxide supports. The complexity of these systems stems from the fact that even for a one-component catalytic cluster or nanoparticle the number of different possible structural forms (isomers) is very large. For the case of alloys particles, the complexity increases even further as each isomeric form gives rise to a large number of secondary structures (homotops) that differ by the placement of the different types of atoms between the sites of that isomer. As a consequence, the configuration space that has to be searched is immense. We are using the parallelized version of the NWChem package installed on Fusion. The current work focuses on pure Pt and Mo and mixed Pt/Mo clusters. So far we have covered the size range from 2 to 13 atoms and made some test runs on a 55 atom cluster. The cas es of low or no symmetry are particularly problematic. Even for a system as small as a 13-atom Pt cluster we repeatedly encountered references to “segmentation error”. The largest number of processors we have used so far is 128. The reason for this is not lack of scalability in performance, but simply the desire to save the very limited resources we have been allocated so far. Our performance tests indicate that we could use profitably hundreds or even thousands of processors in runs on systems with about 50-100 atoms. Our plans are to extend our studies to this size range and beyond. In addition, we plan to add in the computations also the atomistic representation of the supports. The expected number of project members is 4. Project URL: http://www.anl.gov/catalysis-science/index.html Current FY Hours Used: undetermined amount New FY Requested allocation: 990000 Justification: The allocation request is based on estimates made on Fusion and on Carver at NERSC. Tests on Pt_12Mo cluster with the Stuttgart pseudopotential and a basis set of 38 contracted functions per atom performed with 32, 64, and 128 processors indicate full parallel scaling efficiency. Tests on a 55 atom cluster with 128 and 200 processors give a comparable scaling. Thank You, The LCRC Accounts System