The standard approach used here is that the response of the individual meta-atom is dependent on the neighboring meta-atoms. Under periodic boundary conditions, the unit-cell simulated is assumed to be identical. When the full meta-surface is designed, for any meta-atom, closest neighbors will not be identical generally to induce the desired effect on the electromagnetic field. However, suppose the coupling between the metaatoms is weak enough, or the effect from the neighboring metaatoms is slowly varying the field behavior. In that case, simulated metaatoms can be used as an individual building block of metasurface for calculated effect from periodic boundary conditions. Such results will generally yield nice enough results for holography. To improve the design of the metasurface, there are also several different methodologies, like implementing the Gerchberg Saxton algorithm for several iterations dependent on the desired error or utilizing machine learning tools.