Data items in the PHASING_SET_REFLN category record the values
               of the measured structure factors used in a phasing experiment.
               This list may contain information from a number of different
               data sets; _phasing_set_refln.set_id indicates the data set
               to which a given record corresponds.
 
    _phasing_set_refln.set_id           'NS1-96'
    _phasing_set_refln.index_h           15
    _phasing_set_refln.index_k           15
    _phasing_set_refln.index_l           32
    _phasing_set_refln.F_meas_au        181.79
    _phasing_set_refln.F_meas_sigma_au    3.72