Crystalline subrepresentations and neron models

We propose the notion of the crystalline sub-representation functor defined on p-adic representations of the Galois groups of finite extensions of Q(p), with certain restrictions in the case of integral representations. By studying its right-derived functors, we find a natural extension of a formula of Grothendieck expressing the group of connected components of a Neron model of an abelian variety in terms of Galois cohomology.