Originally Posted by

**davebarrass** Hi. Just going over some past exam papers and can't work out how to answer one of the questions as the course notes only use simple examples.

I need to use variational method to estimate the ground state energy of a physical system using a trial wavefunction:

phi = Aexp(-Br/2a) [B and a constants]

I'm then asked to normalise phi using spherical polar coordinates to show

A^2 = (B^3)/(8.pi.a^3)

I know this is done by finding the integral of phi*phi d^3**r** between 0<r<a, 0<theta<pi and 0<phi<2pi but I'm not sure what to do with the exponental function in this integral.

Anyone have any ideas? Thanks for your help.