Durandurdu, Murat2025-09-252025-09-2520140295-50751286-4854https://doi.org/10.1209/0295-5075/105/46001https://hdl.handle.net/20.500.12573/4277Durandurdu, Murat/0000-0001-5636-3183;The stability of magnesium hydride (MgH2) at high pressure is studied using a constant-pressure ab initio technique. Two phase transformations are successfully observed through the simulations. The rutile structure undergoes a phase transformation into a CaCl2-type phase. Further increase in pressure results into a first-order phase transition into an orthorhombic state within Pbcm symmetry. This phase can be considered as a distorted CsF2-type crystal and does not correspond to the previously proposed MgH2 phases. The transformation mechanism of the CaCl2-Pbcm phase change at the atomistic level is successfully characterized and it is found that the CaCl2-to-Pbcm phase change proceeds via an ideal CaF2-type intermediate phase. These phase transformations are also analyzed using total energy-volume calculations.Copyright (C) EPLA, 2014eninfo:eu-repo/semantics/closedAccessArticle10.1209/0295-5075/105/460012-s2.0-84896322858