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Dangerous radioactive waste leftover from the Cold War era nuclear weapons production continues to contaminate sixteen sites around the United States. Although many challenges and obstacles exist in decontaminating these sites, two particularly dicult tasks associated with cleanup of this waste are extracting and separating actinide elements from the remainder of the solution, containing other actinide elements and non actinide elements. Developing eective methods for performing these separations is possible by designing new chelating agents that form stable complexes with actinide elements, and by investigating the interactions between the chelating agents and the actinide elements. In this work, new chelating agents (or ligands) with potential to facilitate the separation of radioactive waste are designed for Th, Pa, and U using relativistic Density Functional Theory (DFT) inconjunction with a high-throughput algorithm. We show that both methodologies can be combined eciently to accelerate discovery and design of new ligands for separation of the radioactive actinides. The main hypothesis that we test with this approach is that the strength of secondary coordination sphere (SCS) can be tuned to increase the selectivity of binding with dierent actinides. More specically, we show that links that connect two of the catecholamide ligands via covalent interactions are then added to increase the overall stability of the complex. The eect of increase in the selectivity is also observed when non-covalent interaction is used between ligands. We apply this approach for Th, Pa, and U, and discover linkers that can be used with other ligands. adding a butene link.