Compilation and deciphering MoS2’s physical properties: Accurate benchmark DFT simulations and assessment of advanced quantum methods

The effect of the cumulant approximations and commonly electronic structure methods predominantly devoted to studying material properties at the atomic and molecular levels is examined in the case of bulk MoS2. The analysis is performed for the investigation of the lattice parameter constants and electronic properties of bulk MoS2 compounds using various Density-functional theory (DFT) calculation methods, within the context of PBE, LDA+U, PBE+U, PBE+U+V, GW, and HSE06 (Heyd–Scuseria–Ernzerhof 2006) theoretical methods. The calculations focus herein on the hexagonal transition metal dichalcogenides (TMDs) structure, which represents the lowest energy crystalline structures. Interestingly, the comparison of the obtained lattice constant parameters with experimental and theoretical results reveals slight overestimations in the PBE calculations, consistent with previous findings. While the cumulant use of the hybrid-HSE06 functional are seen to improve the accuracy of the lattice parameter constants by reducing the percentage error compared to experimental data, the congregated PBE and U calculations are found, on the contrary, to concisely underestimate the lattice parameters of MoS2 due to increased electron localization. Thus, incorporating the Hubbard parameter within the context of the PBE approximation reveals minimal impact on the band gap of MoS2. Furthermore, we show that non-local hybrid calculations, such as HSE06, showcase great sensitivity on the improved electronic properties for MoX2 compounds (X = S, Se, Te), leading to a substantial decrease of the band gap errors. Thus, the HSE06 method is revealed to capture the highest energy band gap, providing thereby new means for accurately determining the band gap and probing statistically the obtaining of unique information regarding the critical aspect of the band gap values of TMDs materials research.