def lyap_lrcf_solver_options(lradi_tol=1e-10,
                             lradi_maxiter=500,
                             lradi_shifts='projection_shifts',
                             projection_shifts_z_columns=1,
                             projection_shifts_init_maxiter=20,
                             projection_shifts_init_seed=None,
                             projection_shifts_implicit_subspace=True):
    """Returns available Lyapunov equation solvers with default solver options.

    Parameters
    ----------
    lradi_tol
        See :func:`solve_lyap_lrcf`.
    lradi_maxiter
        See :func:`solve_lyap_lrcf`.
    lradi_shifts
        See :func:`solve_lyap_lrcf`.
    projection_shifts_z_columns
        See :func:`projection_shifts`.
    projection_shifts_init_maxiter
        See :func:`projection_shifts_init`.
    projection_shifts_init_seed
        See :func:`projection_shifts_init`.
    projection_shifts_implicit_subspace
        See :func:`projection_shifts`.

    Returns
    -------
    A dict of available solvers with default solver options.
    """
    return {'lradi': {'type': 'lradi',
                      'tol': lradi_tol,
                      'maxiter': lradi_maxiter,
                      'shifts': lradi_shifts,
                      'shift_options':
                      {'projection_shifts': {'type': 'projection_shifts',
                                             'z_columns': projection_shifts_z_columns,
                                             'init_maxiter': projection_shifts_init_maxiter,
                                             'init_seed': projection_shifts_init_seed,
                                             'implicit_subspace': projection_shifts_implicit_subspace}}}}