Bridging Experiment and Theory to Reveal Compounds in K–Zn(Cd)–Bi Systems

This study investigates the facile hydride synthesis method guided by theoretical predictions to explore the K– T –Bi ( T = Zn, Cd) phase spaces. Using an adaptive genetic algorithm (AGA) and density functional theory (DFT), candidate compositions are identified for experimental validation via a facile hydrides route, permitting experimental screening of K–Zn–Bi and “empty” K–Cd–Bi systems. The previously reported KZnBi and KZn 2 Bi 2 are synthesized alongside newly discovered KCdBi and KCd 2 Bi 2 . While the AGA and DFT predict the stability of these compounds, structural predictions align with the experiment only for KZnBi and KZn 2 Bi 2 . Single‐crystal X‐ray structure refinements confirm that KZnBi and KZn 2 Bi 2 adopt the hexagonal ZrBeSi‐ and tetragonal ThCr 2 Si 2 ‐structure types, respectively. KCdBi has tetragonal PbClF‐structure type and KCd 2 Bi 2 belongs to the ThCr 2 Si 2 ‐structure type. A trend based on the ratio of the metal ionic radii allows to rationalize variation in the structure types within the AT Bi family ( A = Li–Cs), correctly identifying KCdBi as isostructural to NaZnBi. Thermal stability studied by high‐temperature powder X‐ray diffraction reveals that Zn‐containing compounds melt at higher temperatures (821 K for KZn 2 Bi 2 ) than Cd‐containing KCd 2 Bi 2 (635 K). This study highlights the efficacy of combining rapid synthesis techniques with predictive modeling, though structural predictions show some limitations in accuracy.