Metric-driven search for structurally stable inorganic compounds

We report a facile `metric' for the identification of structurally and dynamically (positive definite phonon structure) stable inorganic compounds. The metric considers charge-imbalance within local substructures in crystalline compounds calculated using first-principles density-functional theory. To exemplify, we chose carbon-based nitrides as it provides large pool unstable phases. showcase how structural information related to Wyckoff symmetry uniquely identifies four new carbon-nitride predicts three phases 4 (C)$:$3 (N) stoichiometry, i.e., C$_{4}$N$_{3}$, which is further confirmed by direct calculations. also satisfy thermodynamic stability mechanical criteria. New possess extraordinary properties, similar diamond, show insulating bandgap ranging from optimal, 1.45 eV (optimal) 5.5 (large gap). structural, electronic, optical properties Pm(1)-C$_{4}$N$_{3}$, discussed detail, indicate possible application optoelectronic photovoltaic technologies. way design, can be used predict any material with three-dimensional bonding network. was able other nitride polymorphs 100$\%$ accuracy. believe that proposed `Metric' will accelerate search unknown unexplored quick filtering without expensive theory