def make_quippy_config(config):
    """Generate the quippy descriptor argument string."""
    cutoff = config['cutoff']
    l_max = config['l_max']
    n_max = config['n_max']
    sigma = config['sigma']
    elems = config['elems']
    species = ' '.join(map(str, elems))
    quippy_config = (
        f'soap cutoff={cutoff} l_max={l_max} n_max={n_max} atom_sigma={sigma} n_Z={len(elems)} Z={{{species}}} n_species={len(elems)} species_Z={{{species}}}'
        )
    return quippy_config
