Title: THE STRUCTURE OF CONCENTRATED Li-AMMONIA SOLUTIONS AS DERIVED FROM MD SIMULATIONS
Author(s): S.Hannongbua, T.Remsungnen (Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand), M.Kiselev (Institute of Solution Chemistry, Russian Academy of Sciences, 153045 Ivanovo, Russia), K.Heinzinger (Max-Planck-Institut f\"{u}r Chemie (Otto-Hahn-Institut), POB 3060, 55020 Mainz, Germany)

The results of Molecular Dynamics simulations of lithium-ammonia solutions over the whole concentration range from 0.5 to 19.6~MPM at 240~K are reported. The pseudopotential theory is employed at the higher concentrations and the direct contribution to the total potential which has been derived from \textit{ab initio} calculations has been supplemented by three-body terms. The resulting partial structure and radial distribution functions are compared in detail with recent X-ray and neutron diffraction studies with isotopic substitution. There is an overall good agreement between simulation and experiment. Differences are discussed. The solvation number of the lithium ion is found to be six for the dilute solution and four for the higher concentrations in analogy to the hydration of Li$^{+}$ found for various aqueous solutions.

Key words: Molecular Dynamics simulation, lithium-ammonia solutions, pseudopotential theory
PACS: 61.20.J, 61.20.Qg, 71.15.Pd