Computing full Electron-Nuclear Interaction Integrals using Obara-Saika Scheme?

Following my previous question [Here](https://chemistry.stackexchange.com/questions/162846/can-electron-repulsion-integrals-be-negative), I had been trying to implement One and Two electron integrals in the code. I am currently stuck at the implementation of the OS Scheme, where I read the references [1] and [2] to look for the implementation. I understood the recursion parts where the electron is transferred from one center to another using the following recursion relations:
$$ \theta^N\_{i+1,j,k,l,m,n}=\theta^N\_{i,j+1,k,l,m,n}-X\_{AB}\theta^N\_{i,j,k,l,m,n}$$
$$ \theta^N\_{i,j,k+1,l,m,n}=\theta^N\_{i,j,k,l+1,m,n}-Y\_{AB}\theta^N\_{i,j,k,l,m,n}$$
$$ \theta^N\_{i,j,k,l,m+1,n}=\theta^N\_{i,j,k,l,m,n+1}-Z\_{AB}\theta^N\_{i,j,k,l,m,n}$$
$$ \theta^N\_{0,0,0,0,0,0} = F\_N(pR^2\_{PC})$$
where A and B are centers of the the basis functions and ordered set (i,k,m) and (j,l,n) are the angular momentum terms in x,y and z direction, and N is the order of Boys function. My question concerns the calculation of total integral from this scheme.


References:


1. Helgaker, \_Modern Electronic Structure Theory
2. Obara. S, and Saikia. A, *Efficient recursive computation of molecular integrals over Cartesian* J. Chem. Phys. 84, 3963 **(1986)**
Gaussian functions


