Europhys. Lett., 63 (4) , pp. 562-568 (2003)
Pressure-induced simultaneous metal-insulator and structural-phase transitions in : A quasiparticle studyS. Lebègue1, 2, 3, M. Alouani1, 2, B. Arnaud4 and W. E. Pickett3
1 Institut de Physique et de Chimie des Matériaux de Strasbourg (IPCMS) UMR 7504 du CNRS - 23 rue du Loess, 67037 Strasbourg, France
2 Max-Planck Institut für Festkörperforschung - D-70506 Stuttgart, Germany
3 Department of Physics, University of California - Davis, CA 95616, USA
4 Groupe Matière condensée et Matériaux (GMCM), Campus de Beaulieu, Bât. 11A 35042 Rennes Cedex, France
(Received 13 February 2003; accepted in final form 16 June 2003)
A pressure-induced simultaneous metal-insulator transition (MIT) and structural-phase transformation (from the B1 to B2 phase) in lithium hydride with about 1.3% volume collapse has been predicted by means of the generalized-gradient approximation (GGA) in conjunction with an all-electron GW approximation method. The local-density approximation (LDA) wrongly predicts that the MIT occurs before the structural phase transition, whereas the GGA predicts the correct transition but with a very small band gap of the B1 phase at the transition. It is also shown that only the use of the GGA together with the zero-point vibration produces an equilibrium lattice parameter, bulk modulus, and an equation of state that are in excellent agreement with experiment.
71.15.Mb - Density functional theory, local density approximation, gradient and other corrections.
71.15.Nc - Total energy and cohesive energy calculations.
71.30.+h - Metal-insulator transitions and other electronic transitions.
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