A pentanary chloride sulfate KBiCl 2 SO 4 (1) is synthesized via a simple solution routine. 1 is crystallized in the chiral orthorhombic P2 1 2 1 2 1 with Z = 4, and its onedimensional structure features a {[BiCl 2 (SO 4 )] − } ∞ chain along the polar axis. Its second-harmonic generation response is approximately 1.7 times that of KDP, and it can achieve phase matchability under the radiation of 1064 nm laser. Its optical energy gap is measured to be 3.95 eV. The density functional theory calculation results indicate that both [BiCl 2 O 3 □] 5− and [SO 4 ] 2− units serve as functional moieties for its promising nonlinear optical performance.

Investigations of inorganic compounds with mixed anions have drawn much attention. Here, three oxysulfides, Sm 3 NbS 3 O 4 (1), Gd 3 NbS 3 O 4 (2), and Dy 3 NbS 3 O 4 (3), are obtained by solid-state reactions. 1 and 2 crystallize in the polar space group Pna2 1 , while 3 crystallizes in the centric space group Pnma. The anionic frameworks of 1 and 2 are built by isolated distorted [NbS 2 O 4 ] 7− octahedra, while [NbS 3 O 4 ] 9− is used for 3. 1 and 2 exhibit phase-matchable second-harmonic-generation (SHG) effects of about 0.3 and 0.4 × AGS at 2.1 μm. The [NbS 2 O 4 ] 7− octahedron was first used as a SHG-active motif for nonlinear-optical (NLO) materials. A systematic analysis of the transformation between these crystal structures, NLO performances, and magnetic behaviors, as well as first-principles theoretical studies, is presented. This work enriches the study on relatively rarely explored NLOactive metal oxysulfides.

Two isostructural adducts CHI 3 •(S 8 ) 3 (1) and AsI 3 •(S 8 ) 3 (2) are synthesized by a simple solution method. Both of them crystallize in noncentrosymmetric R3m, featuring van der Waals interaction linked CHI 3 tetrahedra or SbI 3 trigonal pyramids with crown-like S 8 molecules. Both 1 and 2 show strong SHG responses and phase matchability under either 1.064 or 2.1 μm. The results of DFT calculations indicate that the electron transfer happens from S-3p to I-5p orbitals, and both of them demonstrate indirect band gaps. The NLO effects of 1 and 2 are almost fully contributed from the CHI 3 or AsI 3 units. Compared with AgGaS 2 , their powder laser damage thresholds are ca. 15 and 51 times higher.

Chalcogenide borates were very rarely investigated in the past. As the second selenide borate, YSeBO 2 obtained by a high-temperature solid-state reaction crystallizes in the noncentrosymmetric orthorhombic space group Cmc2 1 with a novel structure type. Its structure consists of two basic building units, [BO 3 ] 3− planar triangles and [YO 3 Se 4 ] 11− pentagonal bipyramids, and features the [YSeBO 2 ] n planar belt. Second-harmonic-generation measurement shows its phase-matchable activity. YSeBO 2 has an optical energy gap of 3.45 eV. Density functional theory calculation is also performed, addressing the electronic structure and nonlinearoptical property.

Inorganic salts with multiple anions recently receive increasing interest in view of their structural diversity and multifunctional properties, and oxysulfides are one type of such salts. Here, three novel oxysulfides...