Returns calculated mesh sampling phonons

        Returns
        -------
        dict
            keys: qpoints, weights, frequencies, eigenvectors, and
                  group_velocities

            Each value for the corresponding key is explained as below.

            qpoints: ndarray
                q-points in reduced coordinates of reciprocal lattice
                dtype='double'
                shape=(ir-grid points, 3)
            weights: ndarray
                Geometric q-point weights. Its sum is the number of grid
                points.
                dtype='intc'
                shape=(ir-grid points,)
            frequencies: ndarray
                Phonon frequencies at ir-grid points. Imaginary frequenies are
                represented by negative real numbers.
                dtype='double'
                shape=(ir-grid points, bands)
            eigenvectors: ndarray
                Phonon eigenvectors at ir-grid points. See the data structure
                at np.linalg.eigh.
                dtype='complex'
                shape=(ir-grid points, bands, bands)
            group_velocities: ndarray
                Phonon group velocities at ir-grid points.
                dtype='double'
                shape=(ir-grid points, bands, 3)

def get_mesh_dict(self):
        """Returns calculated mesh sampling phonons

        Returns
        -------
        dict
            keys: qpoints, weights, frequencies, eigenvectors, and
                  group_velocities

            Each value for the corresponding key is explained as below.

            qpoints: ndarray
                q-points in reduced coordinates of reciprocal lattice
                dtype='double'
                shape=(ir-grid points, 3)
            weights: ndarray
                Geometric q-point weights. Its sum is the number of grid
                points.
                dtype='intc'
                shape=(ir-grid points,)
            frequencies: ndarray
                Phonon frequencies at ir-grid points. Imaginary frequenies are
                represented by negative real numbers.
                dtype='double'
                shape=(ir-grid points, bands)
            eigenvectors: ndarray
                Phonon eigenvectors at ir-grid points. See the data structure
                at np.linalg.eigh.
                dtype='complex'
                shape=(ir-grid points, bands, bands)
            group_velocities: ndarray
                Phonon group velocities at ir-grid points.
                dtype='double'
                shape=(ir-grid points, bands, 3)

        """
        if self._mesh is None:
            msg = ("run_mesh has to be done.")
            raise RuntimeError(msg)

        retdict = {'qpoints': self._mesh.qpoints,
                   'weights': self._mesh.weights,
                   'frequencies': self._mesh.frequencies,
                   'eigenvectors': self._mesh.eigenvectors,
                   'group_velocities': self._mesh.group_velocities}

        return retdict