Single crystals of CoV(2)O(6) were obtained in a closed crucible using a flux method. Magnetic measurements showed that this material displays a large magnetic anisotropy and a 1/3 magnetization plateau under a magnetic field applied along the c axis.

Two new ternary noncentrosymmetric (NCS) isostructural compounds, SnGa 4 S 7 (1) and SnGa 4 Se 7 (2), have been synthesized by a high-temperature solid-state reaction method. Both compounds crystallize in the monoclinic polar space group Pc (7), and their three-dimensional (3D) frameworks are assembled from [SnQ 4 ] tetragonal pyramids and tetranuclear [Ga 4 Q 11 ] units. The two crystals show large second harmonic generation (SHG) conversion efficiencies, high laser-induced damage thresholds (LIDTs), and wide transparent regions in the mid-infrared (MIR) zone. Compound 2 exhibits the largest SHG conversion efficiency among type-I phase-matchable chalcogenides of about 3.8 × AgGaS 2 at 2.05 μm radiation and a high LIDT of 4.6 × AgGaS 2 . Theoretical studies elucidate that the stereochemically active lone-pair (SCALP) electrons of Sn 2+ can significantly improve the polarity of the [SnQ 4 ] unit. Large nonlinear optical (NLO) responses for 1 and 2 originate from the covalent interactions of Sn−Q and the cooperative effects of polarities between the units [SnQ 4 ] and [GaQ 4 ]. Additionally, their comparatively simple chemical composition and high chemical stability give them promise for practical applications.