Hi there,

I am planning to load density matrix obtained from a VQE (variationally quantum eigensolver) in the SAPT0 calculation.

Could you please provide me guidance on how to define the matrices in the calculation?

Any comments would be appreciated.

All the best, Farzad

This is undefined, just like it’s undefined to “load a density matrix” into MP2.

You can create a modified version of SAPT that does allow one to load a density matrix, but that’s not SAPT0, and more importantly, we can’t know “how to define the matrices” for a method you made up yourself.

Thanks for your reply. I just came over a paper that getting density matrices from VQE calculations and used them for SAPT0 calculation (please refer to fig. 2 of Chem. Sci., 2022, 13, 3094). I think it is an interesting workflow. I am wondering if I can reproduce same protocol which might be useful for my research study.

Looking forward to hearing back from you.

Please look at the Psi4Numpy repository, which should show you how to get all the integrals you need.