Accelerated Discovery of Fluorophosphates as Deep‐Ultraviolet Nonlinear Optical Materials in the Y–P–O–F System: Unveiling New Composition‐Structure‐Property Rules

ABSTRACT Fluorophosphates have potential as ultraviolet (UV)/deep‐ultraviolet (DUV) nonlinear optical (NLO) material that is the key to high‐tech solid laser‐based equipment. Despite their potential, experimental exploration of fluorophosphate without targeted chemical composition guidance is inefficient and resource‐intensive. Here, we establish a multi‐step computational workflow that integrates crystal structure prediction, pre‐trained machine‐learning screening, and DFT calculations to efficiently navigate the vast fluorophosphate chemical space. By appling this strategy to the unexplored Y–P–O–F system, we identify four thermodynamically stable fluorophosphates and several UV/DUV NLO candidates with favorable optical performance. Systematic analysis of composition–functional unit relationships reveals a composition‐driven competition between nonmetal P–F and metal Y–F bonding, where the O/P ratio and F content determine whether fluorine substitutes into PO 4 tetrahedra (fluorophosphates) or preferentially coordinates to Y cations (phosphate fluorides), thereby regulating the electronic structure and optical anisotropy. Fluorophosphates are further shown to possess intrinsic advantages in achieving ultrashort phase‐matching wavelengths, with the shortest phase‐matching wavelength scaling inversely with the product of birefringence and bandgap, establishing a quantitative descriptor for UV/DUV NLO materials design. This work not only enables efficient discovery of multicomponent fluorophosphate NLO materials but also provides generalizable insights into composition‐ and structure‐driven design of high‐performance UV/DUV NLO materials.