Ab initio strategy for muon site assignment in wide band gap fluorides

We report on an ab initio strategy based on density functional theory to identify the muon sites. Two issues must be carefully addressed: muon delocalization about candidate interstitial sites and local structural relaxation of the atomic positions due to μ+-sample interaction. Here, we verify our strategy's validity focusing on two wide band gap materials, LiF and YF3, where both μ+ delocalization and crystal lattice relaxation play an important role in determining the μ+ stopping site positions.