LANS Informal Seminar: Dmitry Karpeev

Seminar Title: Recent computational results on classical DFT of electrolytes: PETSc + PyCUDA
Speaker: Dmitry Karpeev, MCS

Date/Time: 2010-05-26 15:00
Location: Bldg 240, Conference Center (1406-1407)

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).