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By using a four-interaction interionic potential, constant-energy (classical microcanonical ensemble) molecular dynamics simulations, at room temperature, A g + ionic positions in α-RbAg4I5 compound are reported. In this crystal structure (cubic with a = 11.23934(3) Å and P4132 as space group) a new site has been found. The unit cell has 16- A g + ions, and its disordered partial occupancies have been the subject of discussion. Some authors report 72 [ = 24(e) + 24(e) + 8(c) + 4(b) + 12(d) or Ag1, Ag2, Ag3, Ag4, Ag5] sites with equal vacancy probabilities (Bradley and Greene), 60 [ = 24(e) + 24(e) + 8(c) + 4(b) or Ag1, Ag2, Ag3, Ag4 respectively] with different probability (Geller), 56 [ = 24(e) + 24(e) + 8(c) + 4(b) or Ag1, Ag2, Ag3] with different probability and 4 sites having zero probability (Hull et al). We report 96 interstitial sites [ = 24(e) + 24(e) + 8(c) + 4(b) + 12(d) + 24(e) or Ag1, Ag2, Ag3, Ag4, Ag5, Ag6, respectively] with different probabilities. The new site was denoted as Ag6 with 0.77% similar to Ag5 (∼0.66%). Good results (occupancy probabilities) compared to experimental data were found. [ABSTRACT FROM AUTHOR]

A rigid-ion empirical pairwise potential for RbAg I including Coulomb (long range), Born–Mayer (short range), charge–dipole and dipole–quadrupole (Van der Waals) interactions, has been tested by molecular dynamics simulation with a statistical ensemble where the number of particle, volume, and total energy are constant, non-pressure (P = 0), and as space group were used. Structural (radial, pair, distribution function) and dynamical behaviour (mean square function) of rubidium, iodines, and silvers were evaluated and compared to experimental data reported at room temperature. The potential parameters were taken from different works. [ABSTRACT FROM AUTHOR]