Laguerre polynomials, new integration rule: Gauss-Laguerre
Our integral is now given by
I=∫∞0r21dr1∫∞0r22dr2∫π0dcos(θ1)∫π0dcos(θ2)∫2π0dϕ1∫2π0dϕ2exp−2α(r1+r2)r12
For the angles we need to perform the integrations over θi∈[0,π] and ϕi∈[0,2π]. However, for the radial part we can now either use
Gauss-Legendre wth an appropriate mapping or
Gauss-Laguerre taking properly care of the integrands involving the r2iexp−(2αri) terms.