  The simulation database of THE THREE HUNDRED Project has been used to pick
synthetic clusters of galaxies with properties close to the observational
targets of the NIKA2 camera Sunyaev-Zeldovich (SZ) Large Program.
Cross-matching of cluster parameters such as mass and redshift of the cluster
in the two databases has been implemented to generate the so-called twin
samples for the Large Program. This SZ Large Program is observing a selection
of galaxy clusters at intermediate and high redshift $\left( 0.5 < z < 0.9
\right)$, covering one order of magnitude in mass. These are SZ-selected
clusters from the Planck and Atacama Cosmology Telescope catalogs, wherein the
selection is based on their integrated Compton parameter values, $Y_{500}$: the
value of the parameter within the characteristics radius $R_{500}$.
  THE THREE HUNDRED hydrodynamical simulations provide us with hundreds of
clusters satisfying these redshift, mass, and $Y_{500}$ requirements. In
addition to the standard post-processing analysis of the simulation, mock
observational maps are available mimicking X-ray, optical, gravitational
lensing, radio, and SZ observations of galaxy clusters. The primary goal of
employing the twin samples is to compare different cluster mass proxies from
synthetic X-ray, SZ effect and optical maps (via the velocity dispersion of
member galaxies and lensing $\kappa$-maps) of the clusters. Eventually, scaling
laws between different mass proxies and the cluster mass will be
cross-correlated to reduce the scatter on the inferred mass and the mass bias
will be related to various physical parameters.
