  We present a first-principles investigation of structural, electronic and
optical properties of bulk crystalline Ag3N, AgN and AgN2 based on density
functional theory (DFT) and many-body perturbation theory. The equation of
state (EOS), energy-optimized geometries, cohesive and formation energies, and
bulk modulus and its pressure derivative of these three stoichiometries in a
set of twenty different structures have been studied. Band diagrams and total
and orbital-resolved density of states (DOS) of the most stable phases have
been carefully examined. Within the random-phase approximation (RPA) to the
dielectric tensor, the single-particle spectra of the quasi electrons and quasi
holes were obtained via the GW approximation to the self-energy operator, and
optical spectra were calculated. The results obtained were compared with
experiment and with previously performed calculations.
