Computational Experience with Nano-material Science Quantum Monte Carlo Modeling on BlueGene/L

Modeling and simulation are necessary for nano-material science, as experiments and appliances are costly. In this work we introduce a typical tool flow used for computational nano-material science and report our computational experience with it. QWalk is a Quantum Monte Carlo simulation tool; one of the main methods in identifying nano-material properties, such as the total energy and the band structure of the material. We explain the tool flow for nano-materials and use QWalk to estimate the total energy of selected molecules. We study the tool´s use for modeling of molecules at the nano level using three selected molecules and give our experience with QWalk´s scalability and the underlying factors affecting it. We discuss the tool´s performance, make our recommendations and try to explain some observations.