Density Functional Theory (DFT) is one of the most successful approaches in the computational condensed matter field. Based on this theory, we would be able to calculate material properties from their ground state density. A central quantity in this theory is exchange-correlation potential of the system which is a universal functional of density. The exact form of this universal functional is unknown, so we need to develop proper approximation. The conventional approximations in this theory are LDA and GGA which are based on homogenous electron gas properties, and are efficient for computing various ground state properties of materials, but are in challenge with excited state properties especially estimation of bandgaps. More recent approximations like Hubbard corrections (U) and hybrid functional were developed for improvement of band gap results, but these methods have some limitations and elaborations. In the case of Hubbard method, first principles determinations of the U parameter is an elaborating task, while hybrid functionals significantly increase the computational costs. The is an alternative method which has come into attention recently. It corrects self energy error and the Kohn Sham eigenvalues around the bottom of the conduction band and the top of valence band and consequently gives very good band gaps. Furthermore, its computational costs is the same as standard LDA and GGA functionals. is a method for calculation of the U parameter. It has some advantages like good accuracy, no need super-cells and primary guess for U parameter and computing U for various orbitals (like p orbital). In this study, we are going to use and methods to calculate band structures and band gaps of several two and three dimensional crystals. In fact, the goal is testing these two procedures and evaluating their advantages and disadvantages.