Surface of glassy GeS[subscript 2]: A model based on a first-principles approach
Name
PhysRevB.90.045423.pdf
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1.2 MB
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Author(s)
Massobrio, C.
Bouzid, A.
Boero, M.
Ori, Guido
Coasne, Benoit Alain
Date Issued
July 2014
Journal
Physical Review B
Publisher
American Physical Society
Citation
Ori, G., C. Massobrio, A. Bouzid, M. Boero, and B. Coasne. “Surface of Glassy GeS[subscript 2]: A Model Based on a First-Principles Approach.” Phys. Rev. B 90, no. 4 (July 2014). © 2014 American Physical Society
Version
Final published version
Abstract
First-principles calculations within the framework of the density functional theory are used to construct realistic models for the surface of glassy GeS[subscript 2](g−GeS[subscript 2]). Both calculations at T = 0 K and at finite temperature (T = 300 K) are considered. This allows for a comparison between the structural and electronic properties of surface and bulk g−GeS[subscript 2]. Although the g−GeS[subscript 2] surface recovers the main tetrahedral structural motif of bulk g−GeS[subscript 2], the number of fourfold coordinated Ge atoms and twofold coordinated S atoms is smaller than in the bulk. On the contrary, the surface system features a larger content of overcoordinated S atoms and threefold coordinated Ge atoms. This effect is more important for the g−GeS[subscript 2] surface relaxed at 0 K. Maximally localized Wannier functions (WF) are used to inspect the nature of the chemical bonds of the structural units present at the g−GeS[subscript 2] surface. We compare the ability of several charge derivation methods to capture the atomic charge variations induced by a coordination change. Our estimate for the charges allows exploiting the first-principles results as a data base to construct a reliable interatomic force field.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
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DOI of Published Version
https://doi.org/10.1103/PhysRevB.90.045423
