Mapping cation-eutaxy ternary with a phenomenological model

Predicting the stability of ternary compounds poses a significant challenge due to the complex interplay of atomic features. Existing approaches often struggle to integrate these parameters into a unified framework, particularly for cation-eutaxy ABX ternary systems, where subtle compositional and bonding interactions govern the dimensionality and stability of III‒V networks. To address this challenge, we developed a phenomenological model that combines electronegativity, ionic size, and charge to predict the stability and classify cation-eutaxy structures within [A‒III‒V] chemical systems. Our model introduces stoichiometry-weighted descriptors to evaluate the relative covalent nature of III‒V and A‒V bonds, bridging gaps left by traditional methodologies. Validation through computational high-throughput screening and the Materials Project database demonstrated its accuracy, successfully classifying 35 known cation-eutaxy ABX compounds and identifying 9 previously unreported candidates. As predicted by the model, experimental synthesis of K₂In₂P₃ and Na₂In₂As₃ confirmed the feasibility and predictive reliability of the proposed framework. While further refinements are needed, this study highlights the potential of integrating intuitive atomic features into a model for predicting cation-eutaxy ternary stability, which could lead to novel layered materials.