I am trying to build a solid-liquid interface to be simulate using molecular dynamics. Since, I would be using ab initio molecular dynamics (cpmd or cp2k), I need the minimum cell dimensions. Please suggest some ways to fix the cell dimensions.
The issues that I am concerned about are given in for example in the science paper (http://science.sciencemag.org/content/303/5658/658.full). It is said that there should be a minimum size of the system (specially in the direction perpendicular to the slab) to attain trustworthy results. I am not able to find how and why? For example, if I take 3-10 layers of atoms for making the surface how to determine which one would yield the trustworthy results?