Two-dimensional (2D) transition metal dichalcogenides (TMDs) show multi-functionality due to their highly adjustable chemical, physical, and electronic properties. Here, structural, electronic, and phonon response are systematically studied for 06 TMDs systems via density functional theory (DFT) simulations. A reversible phase transition is revealed between the semiconducting (2H) phase and the metallic (1T) phase in the stable phases of these TMD systems. Precisely, group-VI TMDs (AB2, A = Mo, W and B = S, Se, Te) are focused in this present calculations. Their electronic behavior is assessed to check the accuracy of few available exchange-correlation (XC) functional, along with van der Waals density functional (vdW-DFs). Here, both spin-orbit coupling (SOC) effects and no SOC (NSOC) cases are considered during the calculations. Changes observed in the electronic band structure and density of states for the 2H and 1T phases are worth noticing, which highlights their potential capabilities for conventional device functionalities. These observations not only enable to find the most accurate XC functional, but also shed light on the potential functionalities of these TMDs materials.

中文翻译：

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评估范德华 TMD 材料 AB2 中准确交换相关函数的评估性能（A = Mo、W 和 B = S、Se 和 Te）

二维 (2D) 过渡金属二硫属化物 (TMD) 由于其高度可调的化学、物理和电子特性而表现出多功能性。在这里，通过密度泛函理论 (DFT) 模拟系统地研究了 06 TMD 系统的结构、电子和声子响应。在这些 TMD 系统的稳定相中，半导体 (2H) 相和金属 (1T) 相之间存在可逆相变。准确地说，本次计算重点关注第 VI 族 TMD（AB2、A = Mo、W 和 B = S、Se、Te）。对它们的电子行为进行评估，以检查少数可用交换相关 (XC) 泛函以及范德华密度泛函 (vdW-DF) 的准确性。这里，计算过程中同时考虑了自旋轨道耦合（SOC）效应和无 SOC（NSOC）情况。 2H 和 1T 相的电子能带结构和态密度的变化值得注意，这凸显了它们在传统器件功能方面的潜在能力。这些观察结果不仅能够找到最准确的 XC 功能，而且还揭示了这些 TMD 材料的潜在功能。