def find_atm_si_multiplicators(atm_containers):
    """
    Get atm flux and wavelength multiplicator from `atm_containers`.
    It assume, all containers have the same multiplicators, so it returns values from first one.

    :param atm_containers: List[AtmDatacontainer];
    :return: Tuple[float, float];

    ::

        (flux multiplicator, wavelength multiplicator)

    """
    for atm_container in atm_containers:
        return atm_container.flux_to_si_mult, atm_container.wave_to_si_mult
    raise ValueError(
        'No valid atmospheric container has been supplied to method.')
