Electronic and vibrational densities of states of ab initio generated nanoporous carbons

We investigate the electronic and vibrational densities of states (eDOS and vDOS, respectively) of nanoporous carbon (np-C) simulationally obtained from a crystalline diamond-like supercell with 216 atoms and a crystalline graphite-like supercell with 256 atoms. The nanoporous structures were generated by an ab initio molecular dynamics process at constant temperature (1000 K) using a density functional code based on the Harris functional, following the procedure implemented by Valladares et al. [1]. The resulting samples are essentially amorphous and their pore sizes fall within the nanometer length scale. The study of total and partial eDOS shows a dominant presence of sp2 hybridization in both models and also shows systems without a gap. In the calculated vDOS an extended spectrum around 300 meV is observed and a clear separation of acoustic and optical modes appears. The eDOS and vDOS obtained are compared to those for amorphous samples, since no experimental determinations for porous materials were found.