Towards Petaflop Computing in Nanoscience

Author: Y. Wang (Pittsburgh Supercomputing Center)

Abstract

Over the last 2-3 decades there has been significant progress in the first principles methods to calculate the physical properties of materials at the quantum mechanics level. These methods have largely been based on the local density approximation (LDA) to density functional theory (DFT). However, nanoscience places new demands on these first principles methods because of the large numbers of atoms, in the range of thousands to millions of atoms, present in even the simplest of nano-structured materials. In this presentation, I will show recent advances in the locally self-consistent multiple scattering (LSMS) method that is making the direct quantum mechanical simulation of nano-structured materials possible. The LSMS method is an order-N approach to the first principles electronic structure calculation. It is highly scalable on massively parallel processing supercomputers, and is best suited for performing large unit cell simulations to study the electronic and magnetic properties of materials with complex structure. Combining the LSMS method with the state of the art terascale supercomputing technology, we are able to accomplish the first step towards understanding the electronic and magnetic structure of nano-structured materials with dimension size close to 10 nanometers (nm). I will demonstrate, as an example, the electronic and magnetic structure calculated for iron and iron-platinum nanoparticles, and I will explain to what extent future petaflop computing systems may enable the realistic quantum mechanical simulation of real nano-structured materials.