Table 1

Atomic positions: average value per layer and the corresponding standard deviation σ_z, for layer + (z > 0) and layer − (z < 0) in non-relaxed, relaxed, and z-mod tb-MoS₂ structures. The atoms of the z-mod structure have the same in-plane xy coordinates as the non-relaxed structure and their z coordinates are calculated from equation (1) with z_AA and Z_AB (i.e., in AB’ and BA’ stacking regions) of the DFT-relaxed structure. For each layer δ_z = |Z_AA − Z_AB|. The four last lines correspond to simple AA and AB’ (BA’) bilayer stackings for which and Z_AB, respectively. All calculations were performed using the LDA pseudopotential, except and that are calculated with the GGA PBE pseudopotential [54] including Van der Waals corrections (D2) [52,56]. The latter calculations show that the displacements obtained by the LDA are qualitatively correct. The values for the two layers are symmetric with respect to z = 0. Distances are in Å.

Structure		S±ext	Mo±	S±int
non-relaxed		±4.96	±3.40	±1.84
relaxed		±4.86	±3.21	±1.56
	σz	0.10	0.10	0.10
	zAA	±5.08	±3.43	±1.78
	zAB	±4.72	±3.07	±1.42
	δz	0.36	0.36	0.36
z-mod		±4.84	±3.19	±1.54
	σz	0.10	0.10	0.10
bilayer AA	zAA	±5.11	±3.50	±1.88
		±4.99	±3.42	±1.86
bilayer AB’ (BA’)	zAB	±4.62	±3.01	±1.39
		±4.67	±3.11	±1.55