Non-LTE model atmospheres are calculated, treating the radiation transfer in the comoving frame and accounting for complex model atoms with, typically, 250 levels and a few thousand spectral lines of He and CNO elements. The temperature stratification follows from radiative equilibrium and flux conservation. In typical models, the ionization stratification shows a stepwise recombination with increasing distance from the star.

These models have been widely applied for the spectral analysis of WR stars in the Galaxy and LMC. WN spectra can be well reproduced in general, while some work is still to be done on WC spectra.

The assumption of inhomogeneities (clumping), which is treated in a first-order approximation, significantly improves the agreement between synthetic and observed spectra with respect to the electron-scattering wings of strong lines. The density contrast which can be estimated from these wings implies considerably lower mass-loss rates than obtained from homogeneous models.

In a new version of our model code, line blanketing by iron-group elements is taken into account. The model atom is simplified by introducing superlevels and superlines, but otherwise the radiation transfer is fully treated. We present first results and discuss the influence of iron on the temperature and ionization stratification. The radiation pressure, which is provided by the models, can be compared with the momentum of the wind. While the former is increased by the iron opacities, the latter is reduced by introducing clumping, so that there is a chance to close the gap previously encountered.