KGdSiSe4 and KGdGeSe4: two rare earth-based selenides with wide bandgaps and large nonlinear optical responses.
Two new rare earth (RE) metal selenides KGdSiSe4 and KGdGeSe4 were synthesized by high-temperature solid-state reactions and structurally characterized by single-crystal X-ray diffraction. Both compounds crystallize in the noncentrosymmetric monoclinic P21 space group and feature layered anionic frameworks composed of...