Tailored synthesis of nonlinear optical quaternary chalcohalides: Ba4Ge3S9Cl2, Ba4Si3Se9Cl2 and Ba4Ge3Se9Cl2.

Tailored synthesis of nonlinear optical quaternary chalcohalides: Ba4Ge3S9Cl2, Ba4Si3Se9Cl2 and Ba4Ge3Se9Cl2.