A spectrum calculation code including the effects of one spectator electron
has been constructed. Assuming that ions with a spectator electron are rel
ated with next ionization stage under local-thermal-equilibrium (LTE), the
spectator orbitals which are treated in this code are determined by the Gri
em's boundary. Excited levels higher than the boundary satisfy the LTE cond
ition approximately. In this paper, the effects of a spectator electron on
the X-ray spectra from Ar ions are discussed. (C) 1999 Elsevier Science S.A
. All rights reserved.