Geometry optimization choice of Force-Field

Hey all,

I'm trying to build an amorphous cell of Cyclohexane and water. for the initial geometry Optimization I'm not sure which force-field do I use. I tried COMPASS and dreiding for Cyclohexane and the the total energy is calculated to be negative for COMPASS. does it mean it's a better choice? I'd appreciate if anybody knows anything about the choice of force-field for different compositions.

Thanks,