Interface Nucleus Complementarity:\nAn Iterative Process\nfor the Discovery of Modular Intermetallics Guided by Chemical Pressure

We present an iterative process for the discovery of\nmodular intermetallic\nstructures based on a recently developed interface nucleus approach.\nThe process begins with the proposal of a suitable geometric motif\nthat may serve as an interface nucleus. We then screen crystallographic\ndatabases for structures containing this motif as potential intergrowth\npartners. The extent to which pairs of these structures are likely\nto combine into more complicated assembles is then assessed with a\nnew chemical pressure-based metric, interface nucleus complementarity\n(<i>INC</i>). Promising combinations of structures are translated\ninto systems for synthesis, with new compounds providing either support\nfor the importance of the original interface nucleus or new geometrical\nmotifs for the next round of analysis. We demonstrate this process\nusing a fragment derived from the σ-phase structure as a starting\npoint, leading to the synthesis of PrMg<sub>4.13</sub>Zn<sub>10.20</sub> and a new motif to seed the next cycle.