First principles calculation of structural phase transformation in Mg 2Si at high pressure

• Published in: Solid state communications Vol. 150; no. 47; pp. 2299 - 2302
• Main Authors: Hao, Jun-Hua, Guo, Zhi-Guang, Jin, Qing-Hua
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2010
• Subjects: C. CRYSTAL06; D. Phase transition; E. High pressure; D. Phase transition; C. CRYSTAL06; E. High pressure
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2010.10.017

First principles calculations of the total energy of Mg 2Si as a function of unit cell volume have been carried out for the cubic anti-fluorite (Fm3m) structure, the orthorhombic phase with anti-cotunnite (Pnma) structure and the hexagonal phase with Ni 2In-type (P6 3/mmc) structure on the basis of density functional theory (DFT). All these calculations are performed with the CRYSTAL06 program package. In agreement with experiment, we also obtained the sequence of high-pressure phases for Mg 2Si as: anti-fluorite → anti-cotunnite → Ni 2In-type. Several structural properties (equilibrium lattice constant, bulk modulus, etc.) of the anti-fluorite structure have been calculated, which are also in agreement with the previous experimental results.