A reactive force field (ReaxFF) for zinc oxide

• Published in: Surface science 2008-03, Vol.602 (5), p.1020-1031
• Main Authors: Raymand, David, van Duin, Adri C.T., Baudin, Micael, Hermansson, Kersti
• Format: Article
• Language: English
• Subjects: Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Construction and use of effective interatomic interactions; Cross-disciplinary physics: materials science; rheology; Density-functional calculations; Exact sciences and technology; Inorganic Chemistry; Kemi; Molecular dynamics; NATURAL SCIENCES; NATURVETENSKAP; Oorganisk kemi; Physics; Surface energy; Surface relaxation and reconstruction; Zinc oxide
• ISSN: 0039-6028; 1879-2758; 1879-2758
• DOI: 10.1016/j.susc.2007.12.023

We have developed a reactive force field (FF) within the ReaxFF framework, for use in molecular dynamics (MD) simulations to investigate structures and reaction dynamics for ZnO catalysts. The force field parameters were fitted to a training set of data points (energies, geometries, charges) derived from quantum-mechanical (QM) calculations. The data points were chosen to give adequate descriptions of (the equations of state for) a number of zinc metal and zinc oxide phases, a number of low-index ZnO surfaces and gas-phase zinc hydroxide clusters. Special emphasis was put on obtaining a good surface description. We have applied the force field to the calculation of atomic vibrational mean square amplitudes for bulk wurtzite–ZnO at 20K, 300K and 600K and we find good agreement with experimental values from the literature. The force field was also applied in a study of the surface growth mechanism for the wurtzite(0001) surface. We find that the growth behavior depends on the presence of surface steps.