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Cristobalite‐type boron phosphate BPO4, an important nonlinear‐optical (NLO) crystal, exhibits nearly the largest bandgap (Eg ≈ 9.3 eV) and a significant second‐harmonic‐generation (SHG) effect (d36 ≈ 0.7 pm V−1) in the deep‐ultraviolet (DUV, < 200 nm) spectral region. However, its conventional tetrahedral framework structure tends to have low structural anisotropy, resulting in a severe deficiency of birefringence (Δn < 0.01), which fails to achieve DUV birefringent phase matching. In this work, the local anisotropy of tetrahedral structures are proposed to enlarge by constructing van der Waals (vdW) anisotropic motifs under synthetic chemical conditions, which can effectively convert unattainable extreme external forces into internal stresses in chemical bond structures. Depending on unique hierarchical vdW assemblies, enormous tetrahedral distortions can be achieved by stable in‐plane or in‐line bond matching between rigid tetrahedral primitives. First‐principles calculations demonstrate that the birefringence of 2D layered and 1D chained BPO4 achieved by vdW engineering are scaled from Δn < 0.01 to 0.07–0.13, with the shortest birefringent phase‐matched wavelengths down to DUV 189–154 nm. The finding is of seminal importance for the design of vdW NLO crystals in structural chemistry and would provide opportunities to explore unique vdW DUV NLO materials under extreme synthetic conditions. [ABSTRACT FROM AUTHOR]

K3Ba3Li2Al4B6 O20F is prepared by solid state reaction of a stoichiometric mixture of K2CO3, BaCO3, Li2CO3, Al2O3, LiF, and H3BO3 (1. [ABSTRACT FROM AUTHOR]

A computer-assisted material design system based on first-principles DFT calculations is employed to predict that NH4Be2BO3F2 possesses nonlinear optical properties, such as deep-UV second harmonic generation capability, very close to those of KBe2BO3F2. [ABSTRACT FROM AUTHOR]

The non-linear optical (NLO) material BiB2O4F is prepared by hydrothermal synthesis employing a 1:20:2 molar mixture of Bi(NO3)3, H3BO3, and NaF (autoclave, 200 °C, 3 d, ≈90% yield). [ABSTRACT FROM AUTHOR]

Single crystals of Be2BO3F are grown by spontaneous nucleation from self-fluxed high temperature solutions of NaBF4, BeO, B2O3, and LiF in the molar ratio of 1-1.5:1-2:0.5-1.5:1-3 (Pt crucible, 800 °C, 2 d). [ABSTRACT FROM AUTHOR]