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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def init_dynamic_structure_factor(self, Qpoints, T, atomic_form_factor_func=None, scattering_lengths=None, freq_min=None, freq_max=None):
 """Initialize dynamic structure factor calculation. ******************************************************************* This is still an experimental feature. API can be changed without notification. ******************************************************************* Need to call DynamicStructureFactor.run() to start calculation. Parameters Qpoints: array_like Q-points in any Brillouin zone. dtype='double' shape=(qpoints, 3) T: float Temperature in K. atomic_form_factor_func: Function object Function that returns atomic form factor (``func`` below):
 f_params = {'Na': [3.148690, 2.594987, 4.073989, 6.046925, 0.767888, 0.070139, 0.995612, 14.1226457, 0.968249, 0.217037, 0.045300], 'Cl': [1.061802, 0.144727, 7.139886, 1.171795, 6.524271, 19.467656, 2.355626, 60.320301, 35.829404, 0.000436, -34.916604],b| def get_func_AFF(f_params):
 def func(symbol, Q):
 return atomic_form_factor_WK1995(Q, f_params[symbol]) return func scattering_lengths: dictionary Coherent scattering lengths averaged over isotopes and spins. Supposed for INS. For example, {'Na': 3.63, 'Cl': 9.5770}. freq_min, freq_min: float Minimum and maximum phonon frequencies to determine whether phonons are included in the calculation. """

        if self._mesh is None:
            msg = ("run_mesh has to be done before initializing dynamic"
                   "structure factor.")
            raise RuntimeError(msg)

        if not self._mesh.with_eigenvectors:
            msg = "run_mesh has to be called with with_eigenvectors=True."
            raise RuntimeError(msg)

        if np.prod(self._mesh.mesh_numbers) != len(self._mesh.ir_grid_points):
            msg = "run_mesh has to be done with is_mesh_symmetry=False."
            raise RuntimeError(msg)

        self._dynamic_structure_factor = DynamicStructureFactor(
            self._mesh,
            Qpoints,
            T,
            atomic_form_factor_func=atomic_form_factor_func,
            scattering_lengths=scattering_lengths,
            freq_min=freq_min,
            freq_max=freq_max)