  We study the conditions under which a generic supergravity model involving
chiral and vector multiplets can admit vacua with spontaneously broken
supersymmetry and realistic cosmological constant. We find that the existence
of such viable vacua implies some constraints involving the curvature tensor of
the scalar geometry and the charge and mass matrices of the vector fields, and
also that the vector of F and D auxiliary fields defining the Goldstino
direction is constrained to lie within a certain domain. We illustrate the
relevance of these results through some examples and also discuss the
implications of our general results on the dynamics of moduli fields in string
models. This contribution is based on [1,2,3].
