Creating and using large grids of precalculated model atmospheres for a rapid analysis of stellar spectra

Aims. We present a database of 43 340 atmospheric models (similar to 80 000 models at the conclusion of the project) for stars with stellar masses between 9 and 120 M-circle dot, covering the region of the OB main-sequence and Wolf-Rayet stars in the Hertzsprung-Russell diagram.Methods. The models were calculated using the ABACUS I supercomputer and the stellar atmosphere code CMFGEN.Results. The parameter space has six dimensions: the effective temperature T-eff, the luminosity L, the metallicity Z, and three stellar wind parameters: the exponent beta, the terminal velocity V-infinity, and the volume filling factor F-cl. For each model, we also calculate synthetic spectra in the UV (900-2000 angstrom), optical (3500-7000 angstrom), and near-IR (10 000-40 000 angstrom) regions. To facilitate comparison with observations, the synthetic spectra can be rotationally broadened using ROTIN3, by covering v sin i velocities between 10 and 350 km s(-1) with steps of 10 km s(-1).Conclusions. We also present the results of the reanalysis of E Ori using our grid to demonstrate the benefits of databases of precalculated models. Our analysis succeeded in reproducing the best-fit parameter ranges of the original study, although our results favor the higher end of the mass-loss range and a lower level of clumping. Our results indirectly suggest that the resonance lines in the UV range are strongly affected by the velocity-space porosity, as has been suggested by recent theoretical calculations and numerical simulations.