Additional results on extensions between p-adic and mod p principal series of G(F)

We complete the results of [10]. Let G be a split connected reductive group over a finite extension F of Q(p). When F = Q(p) we determine the extensions between unitary continuous p-adic and smooth mod p principal series of G(Qp) without assuming the centre of G connected nor the derived group of G simply connected. This shows a new phenomenon: there may exist several non-isomorphic non-split extensions between two distinct principal series. We also complete the computations of self-extensions of a principal series in the non-generic cases when the centre of G is connected. Finally, we determine the extensions of a principal series of G(F) by an "ordinary" representation of G(F) (i.e., parabolically induced from a special representation twisted by a character). In order to do so, we compute Emerton's delta-functor H.Ord(B(F)) of derived ordinary parts with respect to a Borel subgroup on an ordinary representation of G(F).