GW methods

Although HKS-DFT demonstrates satisfactory performance in determining the structural properties of materials, it falls short in accurately predicting band gaps and, in some cases, fails to capture the general characteristics of the conduction band. This limitation arises primarily from the absence of a formal justification to interpret DFT eigenvalues as quasiparticle energies. To address this inherent issue, the GW approximation is widely employed as a remedy, as it generally provides improved values for quasiparticle energies. We aim to propose an efficient and scalable real-space implementation of the GW approximation within the DFT-FE framework. By integrating the GW approximation into the DFT-FE methodology, we seek to enhance the accuracy and reliability of quasiparticle energy predictions, enabling more precise and comprehensive analyses of electronic structure properties in a wide range of materials.