  Competitive solvation of an ion by two or more solvents is one of the key
phenomena determining the identity of our world. Solvation in polar solvents
frequently originates from non-additive non-covalent interactions.
Pre-parametrized potentials poorly capture these interactions, unless the force
field derivation is repeated for every new system. Development cost increases
drastically as new chemical species are supplied. This work represents an
alternative simulation approach, PM7-MD, by coupling the latest semiempirical
parametrization, PM7, with equation-of-motion propagation scheme and
temperature coupling. Using a competitive solvation of
(bis)(trifluoromethanesulfonyl)imide anion in acetonitrile and water, the work
demonstrates efficiency and robustness of PM7-MD.
