SCHEDULE: NOV 10-16, 2007

A New O(N) Method for Petascale Nanoscience Simulations

Session: Posters Reception

Event Type: Poster

Time: 5:15pm - 7:00pm

Session Chair: Tamara K Grimmett

Author(s): Zhengji Zhao, Juan Meza, Lin-Wang Wang

Location: Ballroom Lobby

Abstract:
We present a new linear scaling 3 dimensional fragment (LS3DF) method for ab initio electronic structure calculations. The method is based on a divide-and-conquer approach with a novel scheme to patch up the divided fragments. LS3DF has excellent numerical agreement with direct local density approximation (LDA) calculations and can be used to simulate systems with tens of thousands of atoms. In addition, the method scales to thousands of processors and is thousands of times faster than the comparable direct LDA calculations. We will present performance results of LS3DF on different computer platforms, including IBM SP3 and Cray-XT3/XT4 machines. We will focus on parallel scaling, algorithmic scaling, IO rate, global convergence rate, and the error analysis with different fragment sizes. We will also present results for the computation of dipole moments of CdSe quantum dots, which has shed light on a decades old problem in physics.

Chair/Author Details:

Tamara K Grimmett (Chair)
INL

Zhengji Zhao
Lawrence Berkeley National Laboratory

Juan Meza
Lawrence Berkeley National Laboratory

Lin-Wang Wang
Lawrence Berkeley National Laboratory

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