
In this example the DZP basis of silicon has been optimized using the simplex
procedure. The fdf block is:

%Block PAO.Basis
Si   3     -0.05166
 n=3   0   2   E    93.20134     4.27216
     5.10412     4.04111
     1.00000     1.00000
 n=3   1   2   E    75.77391     6.21218
     6.72537     3.95414
     1.00000     1.00000
 n=3   2   1   E   113.16599     2.84839
     4.18127
     1.00000
%EndBlock PAO.Basis

Study the effect of making the different parameters of the soft confinning potential
cero. How does the tail of the orbitals vary? The total energy? The lattice constant/bulk modulus?

Use the following rule of thumb: Vo=150, rinn=3/4 of Rc. Do the results vary too much?
Can you find a better basis set?
