Density functional theory is a powerful method to predict the electronic properties of molecule/clusters and materials due to accuracy and high computational efficiency. In this method, the electron density is treated as a central variable instead of many-electron wavefunction. The implementation of electron density leads to a significant reduction in the level of difficulty as well as the computational cast. In other words, 3N variables (in the case of many-electron wavefunction) are reduced to only three variables (three Cartesian directions)