Table 1: Model atom summary. The entries for Fe refer actually to superlevels and superlines of a generic element representing the whole iron group from Sc to Ni.

Ion	No. of levels	No. of lines
He  I	17	55
He  II	16	120
He  III	1	0
N  II	1	0
N  III	33	118
N  IV	38	153
N  V	17	80
N  VI	1	0
C  II	3	2
C  III	40	224
C  IV	21	140
C  V	1	0
Fe  III	1	0
Fe  IV	11	49
Fe  V	13	69
Fe  VI	17	121
Fe  VII	11	52
Fe  VIII	9	34
Fe  IX	9	35
Fe  X	1	0
20 ions	261	1252