# How are 1-electron and 2-electron integrals done in PySCF?

I am right now using the PySCF for some quantum chemistry problems. I need to get the parameters, which are labeled $$h_{ij}$$ and $$V_{ijkl}$$. How can I get this done with PySCF?

• +1. Welcome to our new community, and we hope to see much more of you in the future!!! Thank you for contributing your question here, and joining us. The "parameters" to which you refer, are called "integrals", so I've changed the question so that more of our community will know what you're seeking. – Nike Dattani Feb 5 at 19:04

from pyscf import gto

Similarly you can get the 1e- integrals by changing int2e to int1e.
• If he specifically wants $V_{ijkl}$ then aosym='s1' is likely a better option to include in your answer. Additionally, there is no such intor named int1e, so that will raise an Exception - if it is the 'core' Hamiltonian (nuclear + kinetic), then use mol.get_hcore(). That is equivalent to mol.intor('int1e_nuc') + mol.intor('int1e_kin'). – obackhouse Jul 11 at 11:20