8.3 (a) Evaluate the probability density of the electron in H3 at the mid-point of the bond, and plot it as a function of R. (b) Evaluate the difference densities p, = w2 3(y3 + y3) at points along the line joining the two nuclei (including the regions outside the nuclei) for R = 130 pm. The difference density shows the modification to the electron distribution brought about by constructive (or destructive) overlap. Hint. Use the expressions for the coefhicients in eqn 8.17 to obtain y,. The overlap integral S is given in Example 8.1. (c) Repeat the calculation for several values of R