On the location of spikes for the Schrodinger equation with electromagnetic field

We consider the standing wave solutions of the three dimensional semilinear Schrodinger equation with competing potential functions V and K and under the action of an external electromagnetic field B. We establish some necessary conditions for a sequence of such solutions to concentrate, in two different senses, around a given point. In the particular but important case of nonlinearities of power type, the spikes locate at the critical points of a smooth ground energy map independent of B.