A scalable method for ab initio computation of free energies in nanoscale systems

Author

Eisenbach, Markus ; Zhou, Changle ; Nicholson, D.M. ; Brown, G. ; Larkin, J. ; Schulthess, Thomas C.

Author_Institution

Oak Ridge Nat. Lab., Oak Ridge, TN, USA

fYear

2009

fDate

14-20 Nov. 2009

Firstpage

1

Lastpage

8

Abstract

Calculating the thermodynamics of nanoscale systems presents challenges in the simultaneous treatment of the electronic structure, which determines the interactions between atoms, and the statistical fluctuations that become ever more important at shorter length scales. Here we present a highly scalable method that combines ab initio electronic structure techniques, we use the Locally Self-Consitent Multiple Scattering (LSMS) technique, with the Wang-Landau (WL) algorithm to compute free energies and other thermodynamic properties of nanoscale systems. The combined WL-LSMS code is targeted to the study of nanomagnetic systems that have anywhere from about one hundred to a few thousand atoms. The code scales very well on the Cray XT5 system at ORNL, sustaining 1.03 Petaflop/s in double precision on 147,464 cores.

Keywords

Cray computers; ab initio calculations; nanoelectronics; nanomagnetics; statistical analysis; thermodynamics; Cray XT5 system; LSMS technique; ORNL; WL algorithm; WL-LSMS code; Wang-Landau algorithm; ab initio computation; ab initio electronic structure technique; atom; code scale; free energies; locally self-consitent multiple scattering; nanomagnetic system; nanoscale system; statistical fluctuation; thermodynamic properties;

fLanguage

English

Publisher

ieee

Conference_Titel

High Performance Computing Networking, Storage and Analysis, Proceedings of the Conference on

Conference_Location

Portland, OR

Type

conf

DOI

10.1145/1654059.1654125

Filename

6375546