next up previous
Next: Non-LTE Line Blocking and Up: The Concept of Radiation Previous: The Concept of Radiation

Atomic Models

It is obvious that detailed non-LTE spectrum-synthesis calculations require accurate atomic data, since the quality of the synthetic spectra cannot be better than the quality of the input data. Hence, we have to improve the basis of our work - the atomic models - continuously. Presently we have replaced the atomic models of the most important ions of the 149 ionization stages of 26 elements considered in order to improve the quality. Eighty per cent of these improvements were implemented by utilizing the SUPERSTRUCTURE program (Eissner et al. 1974, Nussbaumer & Storey 1978), which uses the configuration-interaction approximation to determine wave functions and radiative data. The remaining part of the data was taken from the Kurucz (1992) line list and from the Opacity Project (cf. Seaton et al. 1994; Cunto & Mendoza 1992); the latter was also a source for photoionization cross-sections. Collisional data have largely become available through the IRON project (see Hummer et al. 1993). Table 1 gives an overview of the affected ions.