Fluorides form model systems with which we can test ideas about muon sites. We therefore propose a series of short experiments on well-defined fluoride systems that will be supported by a programme of DFT+mu; calculations and simulations of the nuclear-dipole coupling Hamiltonian to model the decoherent relaxation. Strongly bound F-mu-F states are favoured in alkali fluorides by the very electronegative nature of fluorine and the small ionic radius of the fluoride ion. But what if F is not in that state? What happens if fluorine happens to be part of a polyatomic anion so that the negative charge is shared between other components of the anion? In that case will the fluorine be a less attractive site for the muon? This experiment is designed to answer these questions by examining a series of carefully chosen compounds in which fluorine is incorporated as part of a more complex anion.