I am trying to map out potential energy of a slab surface + cation interaction, since VASP has been giving me very not-so-reliable results I wanted to know if CP2K have the ability to do such calculations? so i can compare the results
CP2K employs Gaussian basis sets and can do 3D (crystals), 2D (slabs), 1D (wires) and 0D (atoms and molecules) periodic calculations naturally, without inducing fictitious interactions of periodic copies.
Slab calculations are documented in the CP2K manual, see e.g. this example exercise modeling Cyclohexaphenylene on Cu(111).