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Title: Anomalous structural behavior and electronic structure in ZrBe 2H 2: density functional calculations

Abstract

Density functional calculations are reported for ZrBe{sub 2}, ZrBe{sub 2}H{sub 2}, and supercells representing ZrBe{sub 2}H{sub x}. We find that the H positions are soft in the sense that displacements along the hexagonal c axis are energetically favored for some orderings and displacement patterns. This is discussed in relation to the anomalous structural and nuclear magnetic resonance data reported for this compound. The mechanism for this softness is related to the electronic structure, specifically coupling to strongly hybridized bands occurring near the Fermi energy. In particular, certain patterns of H shifts along the c axis strongly mix H s and Zr d bands, leading to strong coupling between these shifts and bands at the Fermi energy and instabilities of phonons with these displacement patterns.

Authors:
 [1];  [2]
  1. ORNL
  2. Universite Paris Sud, Orsay, France
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
968236
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 76; Journal Issue: 7
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRONIC STRUCTURE; FUNCTIONALS; NUCLEAR MAGNETIC RESONANCE; PHONONS

Citation Formats

Singh, David J, and Gupta, Michele. Anomalous structural behavior and electronic structure in ZrBe2H2: density functional calculations. United States: N. p., 2007. Web. doi:10.1103/PhysRevB.76.075120.
Singh, David J, & Gupta, Michele. Anomalous structural behavior and electronic structure in ZrBe2H2: density functional calculations. United States. doi:10.1103/PhysRevB.76.075120.
Singh, David J, and Gupta, Michele. Mon . "Anomalous structural behavior and electronic structure in ZrBe2H2: density functional calculations". United States. doi:10.1103/PhysRevB.76.075120.
@article{osti_968236,
title = {Anomalous structural behavior and electronic structure in ZrBe2H2: density functional calculations},
author = {Singh, David J and Gupta, Michele},
abstractNote = {Density functional calculations are reported for ZrBe{sub 2}, ZrBe{sub 2}H{sub 2}, and supercells representing ZrBe{sub 2}H{sub x}. We find that the H positions are soft in the sense that displacements along the hexagonal c axis are energetically favored for some orderings and displacement patterns. This is discussed in relation to the anomalous structural and nuclear magnetic resonance data reported for this compound. The mechanism for this softness is related to the electronic structure, specifically coupling to strongly hybridized bands occurring near the Fermi energy. In particular, certain patterns of H shifts along the c axis strongly mix H s and Zr d bands, leading to strong coupling between these shifts and bands at the Fermi energy and instabilities of phonons with these displacement patterns.},
doi = {10.1103/PhysRevB.76.075120},
journal = {Physical Review B},
number = 7,
volume = 76,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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