  The electronic density of states (DOS) highlights fundamental properties of
materials that oftentimes dictate their properties, such as the band gap and
Van Hove singularities. In this short note, we discuss how sharp features of
the density of states can be obscured by smearing methods (such as the Gaussian
and Fermi smearing methods) when calculating the DOS. While the common approach
to reach a "converged" density of states of a material is to increase the
discrete k-point mesh density, we show that the DOS calculated by smearing
methods can appear to converge but not to the correct DOS. Employing the
tetrahedron method for Brillouin zone integration resolves key features of the
density of states far better than smearing methods.
