DFT plus μ: Density functional theory for muon site determination

The technique of muon spin rotation (lSR) has emerged in the last few decades as one of the most powerful methods of obtaining local magnetic information. To make the technique fully quantitative, it is necessary to have an accurate estimate of where inside the crystal structure the muon implants. This can be provided by density functional theory calculations using an approach that is termed as DFT + mu, density functional theory with the implanted muon included. This article reviews this approach, describes some recent successes in particular lSR experiments, and suggests some avenues for future exploration.