ACuGaS (A = Rb, Cs): Design and Synthesis of Two New Cavity-Chalcopyrite Chalcogenides Based on "Iterative Substitution" Strategy.

Two new non-centrosymmetric chalcogenides, ACuGaS (A=Rb, Cs) have been successfully synthesized by an "iterative substitution" strategy based on chalcopyrite CuFeS structural template. Benefiting from the substitution of Fe cations by Ga cations, ACuGaS (A = Rb, Cs) exhibit wide suitable band gap of 2.48 and 2.

Pb[OPb](SiO)X (X = Cl, Br): The First Pb-Containing Halogen Silicates with Mirror-Symmetric Pseudo-Aurivillius Bilayers.

Two new congruently melting Pb-containing halogen silicates, Pb[OPb](SiO)X (X = Cl, Br), have been synthesized using a high-temperature solution method. Their crystal structures were determined by single-crystal X-ray diffraction, and both compounds crystallize in the orthorhombic space group . In both structures, the mirror-symmetric bilayer composed of Pb-O polyhedra is observed for the first time in Pb-containing silicates and belongs to α-PbO derivatives and is related to the Aurivillius phase.