Translational rotational coupled motions in molten lithium nitrate

The translational rotational coupled motions will be studied by molecular d ynamics simulations in the case of molten lithium nitrate. Calculating sepa rately the time dependent structure factor F(t, q) for the translation and for the rotation of oxygen atoms in nitrate ions Ne give an evaluation of t he characteristic time of each phenomenum. We find that our results are in good agreement with experiments made in aqueous solutions. Then the couplin g between these two kinds of motions is analyzed for several values of the space variable "q" in the Fourier space. We show that the coupling presents a maximum for q=2 Angstrom(-1) which corresponds to the "q" value where th e static structure factor S(q) is maximum. (C) 1999 Elsevier Science B.V. A ll rights reserved.