Adds ICOHPs of both spin channels for spin polarized compounds
        Returns:
             icohp value in eV

def summed_icohp(self):
        """
        Adds ICOHPs of both spin channels for spin polarized compounds
        Returns:
             icohp value in eV
        """
        if self._is_spin_polarized:
            sum_icohp = self._icohp[Spin.down] + self._icohp[Spin.up]
        else:
            sum_icohp = self._icohp[Spin.up]
        return sum_icohp