  The features of the inner products between all the types of real and
complex-energy solutions of the Schr\"odinger equation for 1-dimensional
cut-off quantum potentials are worked out using a Gaussian regularization. A
general Master Solution is introduced which describes any of the above
solutions as particular cases. From it, a Master Inner Product is obtained
which yields all the particular products. We show that the Outgoing and the
Incoming Boundary Conditions fully determine the location of the momenta
respectively in the lower and upper half complex plane even for purely
imaginary momenta (anti-bound and bound solutions).
