Derivation of potential model for LiAlO2 by simple and effective optimization of model parameters

Displacement cascade simulation of LiAlO2 using molecular dynamics

“…1. We adopted a pairwise potential model [13] for simplicity, with reliance on high ionicity of LiAlO 2 . As mentioned below, the potential model shows good performance about the formation energies of Frenkel pairs and the melting point, which are material properties important for a displacement cascade simulation.…”

“…The Coulombic term was evaluated using the smoothed particle mesh Ewald method (SPME) [14], but the remaining terms were calculated directly with the cut-off distance of 10 Å. In our previous study [13], N 0 , N, and a n were determined to reproduce potential energies evaluated with planewave pseudopotential density functional theory (DFT) in various distorted crystal structures. In consequence, these parameters were obtained as N 0 = 4, N = 6 and a n listed in Ref.…”

“…In consequence, these parameters were obtained as N 0 = 4, N = 6 and a n listed in Ref. [13]. The effective charge of each ion was derived, respectively, from Mulliken population analysis as +0.7e for Li + , À1.1e for O 2À , and +1.5e for Al 3+ .…”

“…See Ref. [13] for more details. For a displacement cascade simulation, the potential model that is used must be able to address point defects.…”

“…For a displacement cascade simulation, the potential model that is used must be able to address point defects. The formation energy of a Li Frenkel pair (a pair of a vacancy and an interstitial of a certain element) was evaluated, respectively, as 2.92 eV by DFT calculation and as 3.07 eV using this potential model [13]. In addition, the formation energies of an O Frenkel pair and an Al Frenkel pair were obtained with the potential model as 6.20 eV and 6.60 eV, respectively.…”