Ab-initio study of magnesium porphyrin dimers and nano arrays

We calculate the electronic band structure and density of states for vertically stacked magnesium porphyrins (H aggregate) and one- and two-dimensional flat nanoarrays (nanoribbons and nanosheets) through DFT calculation with periodic boundary conditions. Furthermore, we investigate the theoretical absorption spectra of magnesium porphyrin dimers using hybrid DFT and the coulomb attenuating method (CAM). We compare results with and without CAM and interpret the qualitative findings in the framework of a simple point-dipole interaction model.