title: First-principles investigations of the pressure-induced structural transitions in Mg(AlH(4))(2).
abstract: A systematic investigation is presented of the high-pressure structural stability of Mg(AlH(4))(2) using a plane-wave pseudo-potential method. The total-energy calculations show that under ambient pressure the structure of α-Mg(AlH(4))(2) found by experiments is more stable than the other proposed structures, and with pressure increasing the α to β (δ-Zr(MoO(4))(2)-type structure) and β to γ (Ca(BF(4))(2)-type structure) transitions occur at 0.67 and 10.28 GPa respectively, accompanied with volume reductions of 6.6% and 8.7%. A detailed study of the electronic structures reveals the bonding characteristics between Al and H and between Mg and H as well as the nonmetallic features of α, β, and γ phases under pressure of up to 20.0 GPa. Their electronic structures are mainly responsible for the relative high-pressure stability of the three phases. Finally, an analysis of their structural relations indicates that it is possible to produce the [Formula: see text] structural transition by applying pressure.
authors.affiliation: National Engineering Research Center, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua road, Shenyang 110016, People's Republic of China.
authors.forename: C H
authors.initials: CH
authors.lastname: Hu
authors.forename: D M
authors.initials: DM
authors.lastname: Chen
authors.forename: Y M
authors.initials: YM
authors.lastname: Wang
authors.forename: D S
authors.initials: DS
authors.lastname: Xu
authors.forename: K
authors.initials: K
authors.lastname: Yang