On the interionic potentials and polarization models in alkali halide crystals

Phase-Transferable Force Field for Alkali Halides

“…Instead of Gaussian charge distributions, one could, e.g., use Slater charge distributions that are known to describe the Coulomb interactions more realistically. ,, Regarding the van der Waals interactions, it has been pointed out earlier that the combining rules have a severe effect on the pair potentials and the properties that are calculated with them. ,, Here we explored a modified Buckingham potential; however, it should be mentioned that there are other efforts in this field. , In addition to the dipole–dipole interaction, some models , calculate the dipole–quadrupole interaction through an extra term in the long-range attractive van der Waals interaction explicitly; this adds an extra parameter in the optimization process but might increase the accuracy of the dispersion description. Along these lines, it is known that many-body interactions play a crucial role in many materials and it was pointed out already in 1987 that the inclusion of them in alkali halides is important to properly describe both elastic and dielectric properties at the same time. Several groups work in this direction and try to account for many-body interactions. ,,,, Nevertheless, inclusion of polarizability in the force field as used here and by Kiss et al yields a good approximation to many-body interactions.…”

“…14,15 In addition to the dipole−dipole interaction, some models 34,37 calculate the dipole−quadrupole interaction through an extra term in the long-range attractive van der Waals interaction explicitly; this adds an extra parameter in the optimization process but might increase the accuracy of the dispersion description. Along these lines, it is known that many-body interactions play a crucial role in many materials 121 and it was pointed out already in 1987 122 that the inclusion of them in alkali halides is important to properly describe both elastic and dielectric properties at the same time. Several groups work in this direction and try to account for many-body interactions.…”

Phase-Transferable Force Field for Alkali Halides

“…14,15 In addition to the dipoledipole interaction, some models 34,37 calculate the dipole-quadrupole interaction through an extra term in the long-range attractive Van der Waals interaction explicitly; this adds an extra parameter in the optimisation process but might increase the accuracy of the dispersion description. Along these lines, it is known that many-body-interactions play a crucial role in many materials 121 and it was pointed out already in 1987 122 that the inclusion of them in alkali halides are important to properly describe both elastic and dielectric properties at the same time. Several groups work in this direction and try to account for many-bodyinteractions.…”