In this dissertation, the development and acceleration of quantum chemistry package(ACE-Molecule) based on Lagrange-sinc basis function are discussed. Also, newly proposed methods based on optimized effective potential based methods for excited states, which is implemented on ACE-Molecule are contained. Applying pseudopotential and projector-augmented-wave methods, the fast convergence of accuracy in DFT calculations with Lagrange basis function is shown. Additionally, for excitation calculations, high accuracies of proposed variation of configuration interaction methods using the optimized effective potential method are validated. On the other hand, acceleration of DFT calculations in physical and numerical manners are included. A technique to smooth out interactions due to the nuclei of atoms, a number of used Lagrange basis functions is cut down without loosing accuracy of calculations and initial guess method for general real-space is introduced. In computational perspective, results of ACE-Molecule applying graphical processing units and large-scale parallel computing are included.