Atomistic calculation of structural and phononic properties of twisted two-dimensional transition-metal dichalcogenide*

Two-dimensional (2D) materials show a wide range of interesting physical phenomena that can be tuned by the twist angle between layers. Here we present atomic structures and phononic properties of various twisted 2D transition-metal dichalcogenides in the range of the twist angle from θ = 0˚ (3R-stacking) to θ = 60˚ (2H-stacking). To study large moiré supercells efficiently, we use an atomistic approach based on intralayer elastic energy from first-principles density functional perturbation theory and the Kolmogorov-Crespi interlayer energy. With this approach, we investigate the effects of twisting on the atomic structure and low-frequency interlayer phonon modes, and compare the results of various stacking combinations.