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.