Deep UV (λ <200 nm) Nonlinear Optics (NLO) crystals are an essential crystal material for obtaining all-solid-state deep-UV lasers. At present, only the invention of Chinese scientists such as Chen Chong days KBe2BO3F2 (KBBF) crystal can be directly in practice the actual output frequency of deep ultraviolet laser. KBBF crystal has been used in our country for the development of a series of unique deep-UV solid-state laser technology and laser source equipment, and in many cutting-edge scientific research has been an important application. However, KBBF crystals have some insurmountable intrinsic defects. For example, the beryllium element of the raw material is highly toxic and has serious habit of lamellar growth, which greatly restricts its commercial production and application process. Therefore, research institutes all over the world are actively exploring the development of a new generation of deep UV NLO crystal materials. The key scientific issue to explore new deep UV NLO crystals is that new materials need to meet both the conflicting performance criteria of "deep UV transmission - high frequency doubling - large birefringence". PAN Shi-Lie, Key Laboratory of Special Environmental Functional Materials and Devices, Chinese Academy of Sciences, Xinjiang Institute of Physics and Chemistry, Chinese Academy of Sciences recently proposed a method based on material simulation to systematically summarize the system of halogen-containing borate (Coord. Chem. Rev. 2016, 323, (BO3F) 4-functional groups into the borate framework design strategy; based on the strategy, successfully screened a series of promising lithium fluoroborate lithium deep NLO crystals (Angew. Chem. Int. Ed. 2017, 56, 3916). On the basis of this work, researchers have successfully designed and synthesized NH4B4O6F (ABF) crystal by referring to the structural characteristics of KBBF crystal and further by substituting NH4 + for K +, (BO3F) 4-substitute (BeO3F) 5-. Experiments show that the material has a very short UV cutoff (156nm), a large multiplication factor (3 × KDP), moderate birefringence to meet the deep UV phase matching (the shortest matching wavelength of 158nm). At the same time, compared with KBBF, ABF crystal structure is more compact, significantly enhanced interlayer interaction, thereby eliminating the layered growth habit, to obtain centimeter-level crystals. In addition, the material does not contain highly toxic beryllium elements, and multiplier effect is KBBF 2.5 times, for deep UV laser light source can achieve higher conversion efficiency. ABF excellent overall performance, is expected to become the next generation of deep UV NLO crystal. Relevant research results published in the "American Chemical Society" on. The research results are strongly supported by the National Natural Science Foundation of China, Chinese Academy of Sciences and Xinjiang Science and Technology Department and other units. (a) ABF deep UV transmission spectrum; (b) refractive index dispersion; (c) phase matching interval; (d) frequency doubling effect