This paper presents ab-initio calculations of the electronic structure of two-dimensional (2D) materials MoS₂ and NbSe₂, as well as hypothetical 2D hexagonal structures of Si and Ge. The study shows that 2D MoS₂ is a semiconductor with a direct band gap of 1.78 eV, similar to its 3D counterpart. In contrast, 2D NbSe₂ is a metal, similar to its 3D counterpart. For 2D hexagonal Si and Ge, the electronic structures are compared to graphene. While 2D hexagonal Si exhibits an electronic structure similar to graphene, showing a linear dispersion around the K point, 2D hexagonal Ge is metallic, unlike graphene. The results indicate that 2D Si may have an electronic structure similar to graphene, making it a potential candidate for 2D materials. However, 2D Ge is metallic, and its electronic structure is different from graphene. The study also highlights the importance of computational methods in understanding the electronic properties of 2D materials. The calculations were performed using density functional theory (DFT) with the PAW method, and the results show that 2D MoS₂ and NbSe₂ have electronic structures similar to their 3D counterparts. The study concludes that 2D Si may be a promising material for future electronic applications due to its similarity to graphene, while 2D Ge is metallic. The results also show that the metallic nature of 2D Ge is more robust than in 3D Ge.This paper presents ab-initio calculations of the electronic structure of two-dimensional (2D) materials MoS₂ and NbSe₂, as well as hypothetical 2D hexagonal structures of Si and Ge. The study shows that 2D MoS₂ is a semiconductor with a direct band gap of 1.78 eV, similar to its 3D counterpart. In contrast, 2D NbSe₂ is a metal, similar to its 3D counterpart. For 2D hexagonal Si and Ge, the electronic structures are compared to graphene. While 2D hexagonal Si exhibits an electronic structure similar to graphene, showing a linear dispersion around the K point, 2D hexagonal Ge is metallic, unlike graphene. The results indicate that 2D Si may have an electronic structure similar to graphene, making it a potential candidate for 2D materials. However, 2D Ge is metallic, and its electronic structure is different from graphene. The study also highlights the importance of computational methods in understanding the electronic properties of 2D materials. The calculations were performed using density functional theory (DFT) with the PAW method, and the results show that 2D MoS₂ and NbSe₂ have electronic structures similar to their 3D counterparts. The study concludes that 2D Si may be a promising material for future electronic applications due to its similarity to graphene, while 2D Ge is metallic. The results also show that the metallic nature of 2D Ge is more robust than in 3D Ge.