First-Principles Studies Of Complex Materials With Defects Using Advanced Density Functionals

The study of defects in materials through density functional theory (DFT) is crucial for understanding their electronic properties and guiding their synthesis for several applications, including solar cells, catalysis, semiconductors, and quantum information. Advanced meta-GGA density functionals such as The Strongly Constrained and Appropriately Normed (SCAN) [1] and r2SCAN [2] have proven to be exceptional in computing the electronic and structural properties of materials, often matching or overcoming the performance of hybrid functionals. Although its robustness and increasing popularity, the performance of SCAN and r2SCAN has not been carefully evaluated for defect calculations and only a few references are available. Furthermore, a new promising meta-GGA known as LAK [3] has appeared, showing an outstanding performance for computing band gaps in semiconductors, however it has not been tested on defect calculations yet. In this work, we assess the strengths and weaknesses of the advanced density meta-GGA functionals through the study of defects on complex materials such as the color centers of diamond and several prototypical solids used to benchmark DFT functionals.