Alain CHAUMONT1, Etienne ENGLER1, Rachel SCHURHAMMER1
1Université de Strasbourg, Strasbourg, France
Numerous Molecular dynamic simulations on Choline Chloride based Deep Eutectic Solvents (DES) have been reported in the literature lately, pointing to the fact that in order to accurately reproduce dynamical properties of the latter using a fixed-charge atomistic Force Fields (FF) one has to resort to charge scaling. Herein, we present an alternative to charge scaling and show that by tweaking the LENNARD-JONES parameters of the oxygen and hydrogen of the hydroxyl function in the GAFF v2.11 FF, we were able to accurately reproduce static, dynamical and structural properties of two commonly used DES, namely ETHALINE (1:2 mixture of Choline Chloride and Ethylene Glycol) and GLYCELINE (1:2 mixture of Choline Chloride and Glycerol). Various computed physico-chemical properties for both mixtures with our altered version of the GAFF v2.11 FF are found in good agreement with experimental data. Most importantly however, is the fact that self-diffusion coefficients for the various components of both ETHALINE and GLYCELINE are found within a maximum deviation of 33% from experimental values, which is at least as good if not better as current scaled-charge FF. Finally, computed radial distribution functions match with those reported in the literature.