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Abstract Processing–structure relationships are at the heart of materials science, and predictive tools are essential for modern technological industries insofar as structure dictates intrinsic properties; however, few theoretical models exist for cation‐ordered perovskites. In this work, a combination of data mining and solid‐state synthesis was employed to collect structural data of 1:2 ordered (triple) perovskites. Three compositions within the (Ba_1 − xSr_x)(Mg_1/3Ta_2/3)O₃system were synthesized using a conventional solid‐state mixed‐oxide method. X‐ray diffraction data showed evidence of long‐range 1:2 B‐site cation ordering for all compositions. Additional data for another 24 1:2 ordered compositions were mined from literature. Correlative models for the deviation in modified tolerance factor (Δt′) were derived for each system, and a general model which is capable of predicting the pseudocubic lattice constants of such perovskites based solely on published ionic‐radii data developed. 

Abstract The present article entails the emergence of diverse crystal polymorphs following thermal quenching into various coexistence regions of binary azobenzene chromophore (ACh)/diacrylate (DA) solution and of azobenzene/nematic liquid crystal (E7) mixture. Development of various crystal topologies encompassing rhomboidal and hexagonal shapes can be witnessed in a manner dependent on thermal quenched depths into the crystal + liquid coexistence region of ACh/DA system. Upon spraying with compressed carbon dioxide (CO₂) fluid, the local temperature gradient is generated resulting in spherulitic morphology showing discrete lamellae undergoing twisting locally in some regions and branched dendrites or seaweeds in another. When ACh/E7 blend is sprayed using compressed CO₂fluid, hierarchical organization of various discrete faceted single crystals including needle, rectangular, rhombus, and truncated hexagonal crystals radiating from the spherulite core can be discerned in a brighter region (off cross‐polarization) polarized optical microscopy (POM) and nematic disclination in a darker cross‐polarized region. Of particular interest is that the observed faceted single‐crystal polymorphs in ACh/E7 may be contrasted to the lamellar twisting and branching observed in the ACh/DA system and plausible mechanisms of polymer spherulitic growth are discussed.