A2Bi2(SO4)2Cl4(A = NH4, K, Rb): achieving a subtle balance of the large second harmonic generation effect and sufficient birefringence in sulfate nonlinear optical materials

A series of sulfates A₂Bi₂(SO₄)₂Cl₄(A = NH₄, K, Rb) were synthesized, achieving a subtle balance of a large SHG effect and sufficient birefringence.