Synthesis, characterizations and theoretical analysis of a noncentrosymmetric sulfate

Herein, a noncentrosymmetric sulfate Rb2Mg2(SO4)(3) was synthesized by high-temperature solid-state reaction, and its single-crystal was grown by spontaneous crystallization technique. Single-crystal X-ray diffraction indicates that Rb2Mg2(SO4)(3) features a three-dimensional framework constituted by corner-sharing MgO6 octahedra and SO4 tetrahedra. Optical characterizations suggest that Rb2Mg2(SO4)(3) is transparent down to 200 nm and exhibits a moderate second-order nonlinear-optical response. Electronic band structure and density of state calculations were performed to elucidate the optical origin. Furthermore, the title compound has good thermal stability up to 1133 K.