A global optimisation study of the low-lying isomers of the alumina octomer (Al$_2$O$_3$)$_8$

David Gobrecht; Leen Decin; Sergio Cristallo; Stefan T. Bromley

doi:10.1016/j.cplett.2018.09.018

paper

A global optimisation study of the low-lying isomers of the alumina octomer (Al $_{2}$ O $_{3}$ ) $_{8}$

arXiv:1810.01957 · doi:10.1016/j.cplett.2018.09.018

Abstract

We employ the Monte-Carlo Basin-Hopping (MC-BH) global optimisation technique with inter- atomic pair potentials to generate low-energy candidates of stoichiometric alumina octomers ((Al $_{2}$ O $_{3}$ ) $_{8}$ ). The candidate structures are subsequently refined with density functional theory calculations employing hybrid functionals (B3LYP and PBE0) and a large basis set (6-311+G(d)) including a vibrational analysis. We report the discovery of a set of energetically low-lying alumina octomer clusters, including a new global minimum candidate, with shapes that are elongated rather than spherical. We find a stability limit for these and smaller-sized clusters at a temperature of $T ≃ 1300 - 1450$ K corresponding to a phase transition in liquid alumina.

19 pages, 9 figures, accepted for publication

A global optimisation study of the low-lying isomers of the alumina octomer (Al2​O3​)8​

Abstract

A global optimisation study of the low-lying isomers of the alumina octomer (Al $_{2}$ O $_{3}$ ) $_{8}$