Resumen
In this paper we use A8 -modules to study the derived category of a finite dimensional algebra over an algebraically closed field. We study varieties parameterising A8 -modules. These varieties carry an action of an algebraic group such that orbits correspond to quasi-isomorphism classes of complexes in the derived category. We describe orbit closures in these varieties, generalising a result of Zwara and Riedtmann for modules.