Energetic consideration of defected rhenium disilicide, ReSi2-x, and the electronic structure of Re4Si7 (ReSi1.75), revisited

In order to re-evaluate the proposed models for the crystal structure of defected rhenium disilicide, ReSi2-x, their electronic energies have been calculated based on their modelled structures, and the model proposed by Harada et al. 【Phil. Mag. 91 (2011) 3108-27】was found to be the most plausible. Though its electronic densities of states calculated showed clear energy bandgap in which its Fermi level was just located, the band structure calculated had a slight overlap of the valence bands and the conduction bands, which could not fully explain the observed semiconducting nature of ReSi2-x. Possibility of Anderson insulation due to randomized Si-vacancies was discussed.