The main program in Appendix A solves for the
total energy of the oxygen atom using your getg() routine. It
initializes with zero density, Rho[]=0, and then iterates
Rho 
[]=Rho[]+alpha*g[], as discussed in class, with alpha=0.25.
This program should converge to a value of -74.473076 hartree in about
30 iterations.