  High-resolution spectra of some chemically peculiar stars clearly demonstrate
the presence of strong abundance gradients in their atmospheres. However, these
inhomogeneities are usually ignored in the standard scheme of model atmosphere
calculations, braking the consistency between model structure and
spectroscopically derived abundance pattern. In this paper we present first
empirical self-consistent stellar atmosphere model of roAp star HD24712, with
stratification of chemical elements included, and which is derived directly
from the observed profiles of spectral lines without time-consuming simulations
of physical mechanisms responsible for these anomalies. We used the LLmodels
stellar model atmosphere code and DDAFIT minimization tool for analysis of
chemical elements stratification and construction of self-consistent
atmospheric model. Empirical determination of Pr and Nd stratification in the
atmosphere of HD24712 is based on NLTE line formation for Prii/iii and Ndii/iii
with the use of the DETAIL code. Based on iterative procedure of stratification
analysis and subsequent re-calculation of model atmosphere structure we
constructed a self-consistent model of HD24712, i.e. the model which
temperature-pressure structure is consistent with results of stratification
analysis. It is shown that stratification of chemical elements leads to the
considerable changes in model structure as to compare with non-stratified
homogeneous case. We find that accumulation of REE elements allows for the
inverse temperature gradient to be present in upper atmosphere of the star with
the maximum temperature increase of about 600K.
