Interatomic Potential Model for Molecular Dynamics Simulation of Lithium Borate Melts/Glasses

Abstract

an improved interatomic potential model was proposed for molecular dynamics simulations of lithium borate melt/ glass systems. charge of ion was reconsidered and a new composition dependent ionic charge model was suggested. a new three-body potential model controlling B-O-B angles was also proposed. The three-body term functioned to avoid square network ring consisted of B-O bonds, without preventing the change of boron coordination number between three and four. The edge-shared tetrahedra of four-coordination boron observed in the previous simulation were cleared by applying this three-body potential model.

A new determination method of interatomic potential for sodium silicate glass simulations

“…The IP1 simulation better reproduced Qn 11 / 32 compared to the IP2 simulation for 0.4 ≦ x ≦ 0.5. In generally, the interatomic potential for MD simulations of glasses is determined to reproduce the glass structures and the physical properties by trial and error [10,11]. In the case of the conventional MD simulation of glasses [10,11], the interatomic potential has been applied to even if the quantitative ratios of the elements were changed, as long as they were composed only of the same element.…”

“…In this work, two different interatomic potentials were applied in MD simulations of glasses with different 9 / 32 compositions: (1) the interatomic potential derived in this work based on first-principles calculations, named IP1, and (2) the interatomic potential determined empirically in a previous work [11], named IP2. The abbreviations IP1 and IP2 are also used to denote the results of MD simulations using the respective potentials.…”

“…Noritake et al [9] and Cormack et al [10] used empirical formulae to determine the charges of silicon and oxide ions as functions of the Na2O/SiO2 ratio in sodium silicate melts/glasses for classical MD simulation. Sawaguchi et al [11] also simulated lithium borate glasses/melts using classical MD with ionic charges determined by empirical equations depending on the Li2O/B2O3 ratio. However, no method to determine the optimal ionic charges based on glass composition for use in classical MD simulation has been established.…”

“…The constants in (2-1) and (2-2) were determined in consideration of the empirical values of zNa and zSi used in a previous study [11]. Equation (2-3) for zO was obtained from the charge neutrality of the crystals.…”

Simulation of borosilicate glasses with non-constant force field molecular dynamics

“…For this reason numerical simulations of mixed glasses are very promoting because it can "view" glass structure at molecular level. To date, a molecular dynamics (MD) simula-tion of silicate, borate and mixed borosilicate glasses was conducted in series of papers [1][2][3][4][5][7][8][9][10][11][12][13][14][15][16][17][18][19]. Most of these works deal with classical MD, except researches [2,17] performed with Car-Parinello (MD) [20] and reax force field [21] (ReaxFF), correspondingly.…”