  Using the renormalization group motivated smoothing technique we study the
semiclassical structure of the pure Yang-Mills vacuum. We carefully check that
identified clusters of topological charge behave like instantons around their
centers. Looking at distance distributions of clusters we find
instanton-antiinstanton pair formation in the deconfined phase. We use suitably
normalized gauge invariant field strength correlators to obtain first
quantitative information on the relative color orientation of instantons. We
give further evidence for a modified instanton profile in the confined phase
and present a simple alternative model for it.
