//j=complex(0,1);
//psi = U*exp(j*k*x);
disp("px = h_cross*k(x)");
disp("With infinite limits of integration, both the numerator and denominator are infinite. For problems of this type, one integrates between the finite limits -LI2 and +L/2 and, in the final result, then assumes that L approaches infinity. This result implies that (E, k) diagrams can be considered plots of electron energy vs. momentum, with a scaling factor h_cross.")