  Rapid decline in fossil fuel energy necessitates the immediate need for
renewable energy resources. Here, we report a previously unexplored class of
nitrides AMN$_2$ keeping renewable energy applications in mind. Using a
detailed structure and stability analysis using first principles simulation, we
discovered twelve such compounds (few of which are already synthesized before),
which are chemically, mechanically and dynamically stable. These twelve
compounds were then evaluated for their suitability for three renewable energy
applications, (i) photovoltaics, (ii) water splitting, and (iii)
thermoelectrics. Careful analysis of electronic structure reveals high optical
transition strength resulting in sharp rise in absorption. This in turn yields
high short circuit current and hence excellent solar efficiency for few
compounds namely CsVN$_2$ and RbVN$_2$. Along with excellent absorption
quality, some compounds show favorable band edge positions compared to water
redox levels and hence are promising as photoelectrodes in
photo(electro)chemical water splitting devices. Mixture of flat and dispersive
bands in the band structure yields both high Seebeck and electrical
conductivity, thus excellent power factor for seven compounds. Simulated
lattice thermal conductivity shows moderate to ultralow values and thus the
possibility of achieving high thermoelectric figure of merit (ZT), even at
lower temperatures. From the experimental perspective, we discuss the possible
challenges that may arise while utilizing these compounds for the desired
applications, and suggest possible pathways to overcome them. We believe such
theoretical prediction of promising materials are extremely useful for new
materials discovery and anticipate rapid response from the experimental
community.
