Fig. 5: Illustration of lattice distortion in type-II derivatives.
From: Large sliding regulation in van der waals layered nonlinear optical ternary chalcogenides
a Side view. b Top view. c Oblique view. Z1 (red), Z2’ (green), and Z3(pink) represent different Z-site atoms in AA/AB-stacked phase. Z1 and Z3 are in the upper layer and Z2’ in the lower layer. The black dashed line represents the interlayer Z…Z pair which is composed of Z1 and Z2’ (Z3 and Z2’) in AA (AB) stacking. \({d}_{{\rm{z}}\ldots {\rm{z}}}\) represents the distance between the paired Z atoms in adjacent layers. \({d}_{\parallel }\) and \({d}_{\perp }\) are its horizontal and vertical components.
