Eur. Phys. J. D (2012) 66: 25
https://doi.org/10.1140/epjd/e2011-20547-7

Regular Article

Thermal stability of (MgO)₁₂ dimers

College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, P.R. China

^a e-mail: chenhs@nwnu.edu.cn

Received: 21 September 2011
Received in final form: 15 December 2011
Published online: 31 January 2012

Abstract

The cagelike (MgO)₁₂ clusters were suggested to assemble the low-density nanoporous crystalline phases by connecting in the edge-to-edge, tetragonal face-to-face and hexagonal face-to-face manners. The stabilities of the (MgO)₁₂ dimers bound in the above manners are investigated using methods of molecular dynamics (MD) and density functional theory (DFT). The MD simulations show that the (MgO)₁₂ dimer connected in the hexagonal face-to-face manner can transform to a group of the hexagonal tubelike structures, and the dimer connected in the tetragonal face-to-face manner can change to other isomers through a 2 × 4 × 6 slab structure. Both isomerizations do not require rearrangements of the ions and they occurs at about 700 K and 1000 K, respectively. The DFT calculations indicate that the energy barriers of the isomerizations are about 1 eV, which suggests a lower isomerization temperature.