  The calibration and validation of scientific analysis in simulations is a
fundamental tool to ensure unbiased and robust results in observational
cosmology. In particular, mock galaxy catalogs are a crucial resource to
achieve these goals in the measurement of baryon acoustic oscillation (BAO) in
the clustering of galaxies. Here we present a set of 1952 galaxy mock catalogs
designed to mimic the Dark Energy Survey (DES) Year 3 BAO sample over its full
photometric redshift range $0.6<z_{\rm photo}<1.1$. The mocks are based upon
488 ICE-COLA fast $N$-body simulations of full-sky light cones and were created
by populating halos with galaxies, using a hybrid halo occupation distribution
- halo abundance matching model. This model has ten free parameters, which were
determined, for the first time, using an automatic likelihood minimization
procedure. We also introduced a novel technique to assign photometric redshift
for simulated galaxies, following a two-dimensional probability distribution
with VIMOS Public Extragalactic Redshift Survey (VIPERS) data. The calibration
was designed to match the observed abundance of galaxies as a function of
photometric redshift, the distribution of photometric redshift errors, and the
clustering amplitude on scales smaller than those used for BAO measurements. An
exhaustive analysis was done to ensure that the mocks reproduce the input
properties. Finally, mocks were tested by comparing the angular correlation
function $w(\theta)$, angular power spectrum $C_\ell$, and projected clustering
$\xi_p(r_\perp)$ to theoretical predictions and data. The impact of volume
replication in the estimate of the covariance is also investigated. The success
in accurately reproducing the photometric redshift uncertainties and the galaxy
clustering as a function of redshift render this mock creation pipeline as a
benchmark for future analyses of photometric galaxy surveys.
