Returns the Dict representation of the densities, {Spin: densities},
        but with a Gaussian smearing of std dev sigma applied about the fermi
        level.

        Args:
            sigma: Std dev of Gaussian smearing function.

        Returns:
            Dict of Gaussian-smeared densities.

def get_smeared_densities(self, sigma):
        """
        Returns the Dict representation of the densities, {Spin: densities},
        but with a Gaussian smearing of std dev sigma applied about the fermi
        level.

        Args:
            sigma: Std dev of Gaussian smearing function.

        Returns:
            Dict of Gaussian-smeared densities.
        """
        from scipy.ndimage.filters import gaussian_filter1d
        smeared_dens = {}
        diff = [self.energies[i + 1] - self.energies[i]
                for i in range(len(self.energies) - 1)]
        avgdiff = sum(diff) / len(diff)
        for spin, dens in self.densities.items():
            smeared_dens[spin] = gaussian_filter1d(dens, sigma / avgdiff)
        return smeared_dens