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Title: Using Pattern Search Methods for Surface Structure Determinationof Nanomaterials

Abstract

Atomic scale surface structure plays an important roleindescribing many properties of materials, especially in the case ofnanomaterials. One of the most effective techniques for surface structuredetermination is low-energy electron diffraction (LEED), which can beused in conjunction with optimization to fit simulated LEED intensitiesto experimental data. This optimization problem has a number ofcharacteristics that make it challenging: it has many local minima, theoptimization variables can be either continuous or categorical, theobjective function can be discontinuous, there are no exact analyticderivatives (and no derivatives at all for categorical variables), andfunction evaluations are expensive. In this study, we show how to apply aparticular class of optimization methods known as pattern search methodsto address these challenges. These methods donot explicitly usederivatives, and are particularly appropriate when categorical variablesare present, an important feature that has not been addressed in previousLEED studies. We have found that pattern search methods can produceexcellent results, compared to previously used methods, both in terms ofperformance and locating optimal results.

Authors:
; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Director. Office of Science. Advanced ScientificComputing Research
OSTI Identifier:
919920
Report Number(s):
LBNL-57541
Journal ID: ISSN 0953-8984; JCOMEL; R&D Project: K11116; BnR: KJ0101030; TRN: US0806510
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Journal of Physics: Condensed Matter
Additional Journal Information:
Journal Volume: 18; Journal Issue: 39; Related Information: Journal Publication Date: 10/04/2006; Journal ID: ISSN 0953-8984
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 99 GENERAL AND MISCELLANEOUS; ELECTRON DIFFRACTION; OPTIMIZATION; PERFORMANCE; SURFACES; low energy electron diffraction(LEED) surface structuredetermination pattern search methods (GPS) inverse problem globaloptimization categorical variables

Citation Formats

Zhao, Zhengji, Meza, Juan, and Van Hove, Michel. Using Pattern Search Methods for Surface Structure Determinationof Nanomaterials. United States: N. p., 2006. Web. doi:10.1088/0953-8984/18/39/002.
Zhao, Zhengji, Meza, Juan, & Van Hove, Michel. Using Pattern Search Methods for Surface Structure Determinationof Nanomaterials. United States. https://doi.org/10.1088/0953-8984/18/39/002
Zhao, Zhengji, Meza, Juan, and Van Hove, Michel. 2006. "Using Pattern Search Methods for Surface Structure Determinationof Nanomaterials". United States. https://doi.org/10.1088/0953-8984/18/39/002. https://www.osti.gov/servlets/purl/919920.
@article{osti_919920,
title = {Using Pattern Search Methods for Surface Structure Determinationof Nanomaterials},
author = {Zhao, Zhengji and Meza, Juan and Van Hove, Michel},
abstractNote = {Atomic scale surface structure plays an important roleindescribing many properties of materials, especially in the case ofnanomaterials. One of the most effective techniques for surface structuredetermination is low-energy electron diffraction (LEED), which can beused in conjunction with optimization to fit simulated LEED intensitiesto experimental data. This optimization problem has a number ofcharacteristics that make it challenging: it has many local minima, theoptimization variables can be either continuous or categorical, theobjective function can be discontinuous, there are no exact analyticderivatives (and no derivatives at all for categorical variables), andfunction evaluations are expensive. In this study, we show how to apply aparticular class of optimization methods known as pattern search methodsto address these challenges. These methods donot explicitly usederivatives, and are particularly appropriate when categorical variablesare present, an important feature that has not been addressed in previousLEED studies. We have found that pattern search methods can produceexcellent results, compared to previously used methods, both in terms ofperformance and locating optimal results.},
doi = {10.1088/0953-8984/18/39/002},
url = {https://www.osti.gov/biblio/919920}, journal = {Journal of Physics: Condensed Matter},
issn = {0953-8984},
number = 39,
volume = 18,
place = {United States},
year = {Fri Jun 09 00:00:00 EDT 2006},
month = {Fri Jun 09 00:00:00 EDT 2006}
}