``getRho''

Write a function of the below prototype in ``physics.c'' which computes the quantity

$$\mbox{Rho}(r)=\sum_{n\ell} F_{n\ell} \left\vert\Psi_{n\ell}(r)\right\vert^2,$$

where $F_{n\ell}$ represents the filling of each of the states.

void getRho(double *Rho,
       double ***Psi, double **F, int lmax, int *nmax, int N)

Output:

• Rho[k]: $4 \pi r^2 n(r[k])$ for all grid points r[k]

Input:

• Psi[l][n][k]: values of normalized $\Psi_{n\ell}(r[k])$
• F[l][n]: shell occupancies
• lmax: maximum angular momentum to consider (l=0 through l=lmax)
• nmax[l]: maximum number of nodes sought for angular momentum l
• N: number of intervals for the grid