Computing the equivariant Brauer group

Let [Formula: see text] be a smooth projective rational variety carrying a regular action of a finite abelian group [Formula: see text]. We give examples of effective computation of the Brauer group of the quotient stack [Formula: see text] in dimensions [Formula: see text] and [Formula: see text] using residues in Galois cohomology and the geometry of fixed loci. In particular, we compute [Formula: see text] for all [Formula: see text]-minimal del Pezzo surfaces.