Comparing lattice energies (enthalpies) obtained from a classical force field and ab initio calculations is certainly one way to validate the former. In this case you would run two sets of simulations: one with the solid phase, as you suggest, and one with isolated particles (e.g., ideal gas). The difference between enthalpies of the crystal and ideal gas would be the lattice energy (enthalpy). Depending on your subject, there may be more appropriate ways test a force field. If you are interested in solutions rather than crystals, comparing lattice energies may not be the most informative test. Solvation free energies and enthalpies along with diffusion coefficients may give you a better idea.

Thanks Lukas for your reply. I did compute the lattice energy by minimizing the structure of the solid phase and gas phase. Indeed the value is comparable with experiment which is not a bad test already. But as you correctly mentioned, since I am interested finally to study some mechanism, i have to optimize the force field for some other properties.