A non-centrosymmetric chalcohalide synthesized through the combination of chemical tailoring with aliovalent substitution.

A new non-centrosymmetric (NCS) chalcohalide, [Sr 4 Cl 2 ][Ge 3 S 9 ], was successfully designed and synthesized through combining chemical tailoring with aliovalent substitution strategies from the maternal [NaSr 4 Cl][Ge 3 S 10 ]. It can exhibit a large SHG effect (0.97 × AgGaS 2 ), a wide band gap of 3.71 eV, and a high LDT (∼16 × AgGaS 2 ). These results indicate that [Sr 4 Cl 2 ][Ge 3 S 9 ] may be a potential infrared nonlinear optical crystal.