On certain moduli spaces of ideal sheaves and Donaldson-Thomas   invariants
  We determine the structure of certain moduli spaces of ideal sheaves by generalizing an earlier result of the first author. As applications, we compute the (virtual) Hodge polynomials of these moduli space, and calculate the Donaldson-Thomas invariants of certain 3-folds with trivial canonical classes. 
Sheldon Katz, Wei-Ping Li, Zhenbo Qin