  A comprehensive hybrid library of synthetic stellar spectra based on three
original grids of model atmosphere spectra by Kurucz (1995), Fluks et al.
(1994), and Bessell et al. (1989, 1991) is presented. The combined library is
intended for multiple-purpose synthetic photometry applications and is
constructed in order (i) to cover the largest possible ranges in Teff, log g,
and [M/H]), (ii) to provide flux spectra with useful resolution on the uniform
grid of wavelengths, and (iii) to provide realistic synthetic broad-band colors
for the largest possible parameter and wavelength ranges. For each value of the
effective temperature and for each wavelength, we calculate the correction
function that must be applied to a (theoretical) solar-abundance model flux
spectrum which yields synthetic UBVRIJHKL colors matching the (empirical)
color-temperature calibrations derived from observations. The calibration
algorithm is designed to preserve the original differential grid properties
implied by metallicity and/or luminosity changes in the new library. The
corresponding color calibration is described in some detail.
