LDA+Gutzwiller approach for treating correlated electrons in color center defects

Color center defects are an emerging platform for quantum information science applications. In many color center defects, electrons are tightly bound to localized defect orbitals meaning that a careful treatment of electronic correlations is necessary to properly describe their physics. Here we develop the LDA+Gutzwiller theory for treating electronic correlations for localized defect electrons, which has previously been successfully used to describe localized 4f electrons in lanthanide materials. We show results for a few well-known defects and compare with other methods. We also discuss the aspects of the LDA+Gutzwiller approach that make it particularly well suited for computing defect systems, including its scalability, variational formulation, and accuracy in describing a wide range of correlations in systems.