- #1

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## Homework Statement

Hello at all!

I have to calculate total energy for a nucleons system by equation:

##E_{tot}=\frac{1}{2}\sum_j(t_{jj}+\epsilon_j)##

with ##\epsilon_j## eigenvalues and:

##t_{jj}=\int \psi_j^*(\frac{\hbar^2}{2m}\triangledown^2)\psi_j dr##

My question is: if I'm in spherical coordinates, should I use Laplacian defined by:

##\triangledown^2=\frac{1}{r}\frac{\partial^2 }{\partial r^2}r-\frac{l^2}{r^2}##

or

##\triangledown^2=\frac{1}{r}\frac{\partial^2 }{\partial r^2}r## ?

## Homework Equations

## The Attempt at a Solution

At the moment I try to use

##\triangledown^2=\frac{1}{r}\frac{\partial^2 }{\partial r^2}r##

I'm not sure it's the right solution...

Could someone help me?

Thanks!