Fig. 2

Shift of calculated fundamental bands for bulk MoS ₂. Parameters obtained at FR: \( {\omega}_{A_{1 g, calc}} \) = 412 cm⁻¹ and \( {\omega}_{E_{2 g, calc}} \) = 388 cm⁻¹, to experimental meanings, \( {\omega}_{A_{1 g, \exp }} \) = 408 cm⁻¹ (curve 2) and \( {\omega}_{E_{2 g, \exp }} \) = 382 cm⁻¹ (curve 4) due to FR; Γ ₊ = Γf(T), \( f\left( T=300 K\right)=\left[1+ n\left({E}_{2 g}^2\right)+ n\left({E}_{2 g}^1\right)\right]=3.8 \); two studied FR correspond to different anharmonic constants: Γ(A _1g , CT) = 2.4 cm⁻¹, \( \varGamma \left({E}_{2 g}^1, CT\right)=4.5 \) cm⁻¹; (CT in Fig. 2 is described by enough broad band due to the dispersion of phonons [18, 19] and the centre of gravity CT is shown by arrow at ω = 423 cm⁻¹; because only shift of bands due to FR is important for both fundamental bands, the same initial intensity is taken)