Center for Computational Sciences, Oak Ridge National Laboratory
Beyond Petascale Computing: WL-LSMS, Scalable Calculations of Thermodynamics of Magnetic Systems from First Principles
Wednesday, June 9, 12:00 – 1:00 PM
Room 103, PSC (300 S. Craig Street in Oakland)
Pizza and soft drinks will be provided.
ABSTRACT: Density Functional calculations have proven to be a powerful tool to study the ground state of many materials. For finite temperatures the situation is less ideal and one is often forced to rely on models with parameters either fitted to zero temperature first principles calculation or experimental results. This approach is especially unsatisfactory in inhomogeneous systems, nano particles, or other systems where the model parameters could vary significantly from one site to another.
Here we describe a possible solution to this problem by combining classical Monte Carlo calculations – the Wang-Landau method in this case – with a first principles electronic structure calculation, specifically our locally self-consistent multiple scattering code (LSMS). The combined code shows superb scaling behavior on massively parallel computers.
The code sustained 1.836 Petaflop/s on 223,232 cores of the Cray XT5 jaguar system at Oak Ridge.