Seminar Details:

LANS Informal Seminar
"Recent computational results on classical DFT of electrolytes: PETSc + PyCUDA"

DATE: May 26, 2010

TIME: 15:00:00 - 16:00:00
SPEAKER: Dmitry Karpeev, MCS
LOCATION: Bldg 240, Conference Center (1406-1407), Argonne National Laboratory

Description:
I will discuss our recent work on calculation of ion density profiles in confined geometries using the classical density functional theory framework. Essentially, the problem here is that of minimization of a highly nonlinear functional that describes the (near) equilibrium profiles of charged hard sphere liquids. This is a computationally intensive problem integro differential problem that is poorly amenable to treatment with Newton's method. In particular, the most computationally-expensive step results from an application of a "pseudo-convolution" operator within a continuation loop. In order to accelerate this computation we devised a spectral quadrature approach, which is well-suited for GPU acceleration and doesn't suffer from the use of single-precision arithmetic. Coupling our original PETSc DFT code to PyCUDA resulted in a substantial acceleration of the overall calculation and enabled substantially more interesting computations.

I will outline the DFT model of ionic channel permeation, outline our computational approach to it and discuss the CUDA-based results and their incorporation into the PETSc framework.

This is joint work with Matthew Knepley (UofC), Peter Brune (UofC) and Dirk Gillespie (Rush).


 

Please send questions or suggestions to Debojyoti Ghosh: ghosh at mcs dot anl dot gov.