Method returning a dictionary of projections on elements and specific
        orbitals

        Args:
            el_orb_spec: A dictionary of Elements and Orbitals for which we want
                to have projections on. It is given as: {Element:[orbitals]},
                e.g., {'Si':['3s','3p']} or {'Si':['3s','3p_x', '3p_y', '3p_z']} depending on input files

        Returns:
            A dictionary of projections on elements in the
            {Spin.up:[][{Element:{orb:values}}],
            Spin.down:[][{Element:{orb:values}}]} format
            if there is no projections in the band structure returns an empty
            dict.

def get_projections_on_elements_and_orbitals(self, el_orb_spec):
        """
        Method returning a dictionary of projections on elements and specific
        orbitals

        Args:
            el_orb_spec: A dictionary of Elements and Orbitals for which we want
                to have projections on. It is given as: {Element:[orbitals]},
                e.g., {'Si':['3s','3p']} or {'Si':['3s','3p_x', '3p_y', '3p_z']} depending on input files

        Returns:
            A dictionary of projections on elements in the
            {Spin.up:[][{Element:{orb:values}}],
            Spin.down:[][{Element:{orb:values}}]} format
            if there is no projections in the band structure returns an empty
            dict.
        """
        result = {}
        structure = self.structure
        el_orb_spec = {get_el_sp(el): orbs for el, orbs in el_orb_spec.items()}
        for spin, v in self.projections.items():
            result[spin] = [[{str(e): collections.defaultdict(float)
                              for e in el_orb_spec}
                             for i in range(len(self.kpoints))]
                            for j in range(self.nb_bands)]

            for i, j in itertools.product(range(self.nb_bands),
                                          range(len(self.kpoints))):
                for key, item in v[i][j].items():
                    for key2, item2 in item.items():
                        specie = str(Specie(re.split(r"[0-9]+", key)[0]))
                        if get_el_sp(str(specie)) in el_orb_spec:
                            if key2 in el_orb_spec[get_el_sp(str(specie))]:
                                result[spin][i][j][specie][key2] += item2
        return result