Hi, I want to compute inner products of the form [tex]\langle n,l+1,m+1|n,l-1|m+1\rangle[/tex] where [itex]|n,l,m\rangle[/itex] are hydrogen atom eigenfunctions. Whats the best way to do this, without writing them in the position space representation (i.e. evaluating volume integrals)? Are there any known identities to do this calculation? Thanks in advance, Vivek.