TY - JOUR
T1 - A theoretical study of selenium I under high pressure
AU - Akbarzadeh, H.
AU - Clark, S.J.
AU - Ackland, G.J.
N1 - Cited By (since 1996):19
Export Date: 22 November 2013
Source: Scopus
Art. No.: 018
PY - 1993/10/25
Y1 - 1993/10/25
N2 - Using recently developed codes for density-functional total-energy calculations we trace the structural and electronic response of the hexagonal phase of selenium to applied pressure. We find that the anomalous linear expansion coefficient is well reproduced, and the structure reduces its volume by straightening its twofold-coordinated chains and bringing them closer together. The characteristic overbinding of the local-density approximation causes an effect akin to a spurious pressure on the system rather than a straightforward volume rescaling. The model also predicts a band gap closing rapidly with pressure within the same structural space group. This is not the observed metallization pressure, which in practice is induced by a structural phase transition. We further show that the valence bands are correctly associated with covalent bonds, lone pairs and s-type atomic orbitals, with the lone pairs being the least strongly bound.
AB - Using recently developed codes for density-functional total-energy calculations we trace the structural and electronic response of the hexagonal phase of selenium to applied pressure. We find that the anomalous linear expansion coefficient is well reproduced, and the structure reduces its volume by straightening its twofold-coordinated chains and bringing them closer together. The characteristic overbinding of the local-density approximation causes an effect akin to a spurious pressure on the system rather than a straightforward volume rescaling. The model also predicts a band gap closing rapidly with pressure within the same structural space group. This is not the observed metallization pressure, which in practice is induced by a structural phase transition. We further show that the valence bands are correctly associated with covalent bonds, lone pairs and s-type atomic orbitals, with the lone pairs being the least strongly bound.
KW - SE
KW - TE
KW - PSEUDOPOTENTIALS
KW - TRANSITIONS
KW - SYSTEMS
KW - STATE
KW - GAPS
M3 - Article
VL - 5
SP - 8065
EP - 8074
JO - Journal of Physics: Condensed Matter
JF - Journal of Physics: Condensed Matter
SN - 0953-8984
IS - 43
ER -