I am trying to evaluate 1- and 2-electron integrals using PySCF trough this code:
Hij = mol.intor('int1e_kin') + mol.intor('int1e_nuc')
Vijkl = mol.intor('int2e')
where I previously defined mol
in a particular basis.
I am new in this software and I am reading the basic tutorials that offers the project's site here, but so far I can't find if the elements Vijkl of the 2-electron integrals are define in the chemist's notation, $$ V_{ijkl} = (ij|kl) = \int \frac{\phi^*_i(\mathbf{r}_1)\phi_j(\mathbf{r}_1)\,\phi^*_k(\mathbf{r}_2)\phi_l(\mathbf{r}_2)}{|\mathbf{r}_1 - \mathbf{r}_2|}\,d\mathbf{r}_1d\mathbf{r}_2, $$ or physicist's notation, which is $$ V_{ijkl} = \langle ij|kl \rangle = \int \frac{\phi^*_i(\mathbf{r}_1)\phi_j^*(\mathbf{r}_2)\,\phi_k(\mathbf{r}_1)\phi_l(\mathbf{r}_2)}{|\mathbf{r}_1 - \mathbf{r}_2|}\,d\mathbf{r}_1d\mathbf{r}_2. $$
I am assuming that the program uses chemist's notation. Am I right? And, if so, is it a way to easily convert the array into the other convention? Thank you all in advanced.
pyscf
chemist notation
andelectron integrals
gave these hits for fci and cc. From these pages, they mention that MO integrals are treated in chemist’s notation. $\endgroup$