Molecular dynamics studies of complexing in binary molten salts with polarizable anions: MAX₄

Anion polarizations have been introduced in a molecular dynamics simulation of a complexing ionic liquid MAX4 similar to tetrachloroaluminates. The influence of the polarizability on the structure of the melt has been deduced from the radial distribution functions, the numbers of nearest and next nearest neighbor pairs, the distribution of coordination numbers, and the angular distribution of various triplets. Surprisingly, A₂X₆ molecular species, similar to those postulated to exist in acid haloaluminate melts, were detected in our simulated "neutral" melt. The stability of other species (e.g., A₂X₇^- and A ₃X₁₀^-) that were present in the simulated MAX₄ melt with nonpolarizable X anions decreased when polarization was introduced.