Solvents simulation

Dear all,

Could anyone please help me with simulation of a box containing water and oil?

Is this possible to run a simulation for a box without any macromolecules?

If yes, do I need to change the mdp files?

Many thanks in advance.

.mdp contents are largely a function of the force field used (appropriate nonbonded and constraint settings) and the rest is rather boilerplate for the most part.