Molecular Dynamics-based Simulations of Bulk/Interfacial Structures and Diffusion Behaviors in Nuclear Waste Glasses

Article history: Received 5 June 2016 Received in revised form 21 September 2016 Accepted 22 September 2016 Available online 21 October 2016 A set of empirical potentials have been developed to enablemolecular dynamics simulations of oxide glasseswith themost common glass formers: silica, boron and aluminum oxides. Built upon the recent borosilicate potentials, this set of partial charge effective potentials features composition dependent variable atomic charges and pairwise short range interactions that ensure high computational efficiency. They can correctly reproduce the short range structure features of boroaluminosilicate glasses including [SiO4] tetrahedral network, aluminum coordination, and, importantly, the coordination change of boron as a function of composition. By using the newly developed potentials, a series of sodium boroaluminosilicate glasses were simulated and the structures analyzed in terms of bond distance, bond angle, and coordination number, which were compared with available theoretical, simulation and experimental results. Structural analysis such as polyhedral connectivity analysis, Q analysis, and ring size distribution were obtained to investigate themedium range structure features of these glasses. Furthermore,mechanical properties such as Young's, shear and bulkmoduliwere calculated andwere found to be in good agreementwith experimental data. The vibrational density of stateswas also calculated and comparedwith previous MD and ab initio results. The results show B and B had distinctive spectra features and vibrational spectra were in good agreement with earlier ab initio studies. © 2016 Elsevier B.V. All rights reserved.