:return: the number of nlm orbitals for the basis set

def set_n_nlmo(self):
        """
                :return: the number of nlm orbitals for the basis set
        """

        nnlmo = 0

        data_tmp = self.data
        data_tmp.pop('lmax')
        data_tmp.pop('n_nlo')
        data_tmp.pop('preamble')

        for l_zeta_ng in data_tmp:
            l = l_zeta_ng.split("_")[0]
            nnlmo = nnlmo + (2 * int(l) + 1)

        return str(nnlmo)