The development of efficient sources of terahertz (THz) radiation remains one of the most pressing technological challenges due to the so-called “THz gap.” Current solutions based on inorganic and organic crystals, although well studied, fall short of providing the required efficiency, scalability, or stability. In this work we introduce a novel proof-of-concept approach exploring coordination compounds—an entirely new and unexplored class of materials—as potential THz generators. Leveraging structural data from the Cambridge Structural Database (CSD), we apply Density Functional Theory (DFT) calculations to zinc coordination compounds in order to evaluate their hyperpolarizability, crystal packing, and non-centrosymmetric symmetry requirements. This systematic, data-driven strategy provides the first evidence that coordination compounds may fill the current gap between conventional materials and the needs of emerging THz technologies. 

A major bottleneck in this research direction is the synthesis of suitable single crystals, where achieving non-centrosymmetric phases with the right packing density is particularly demanding. To address this, we propose the use of Bayesian optimization as a guiding framework to adjust and refine experimental conditions for crystal growth. In the longer term, as more DFT-derived data on coordination compounds accumulate, this workflow could be accelerated further through machine learning models capable of predicting hyperpolarizability without the need for full quantum-chemical calculations. Together, these elements outline a forward-looking pathway toward establishing coordination compounds as a promising new class of nonlinear optical materials for THz generation, with the potential to bridge a longstanding technological gap.