Open-shell sapt calaculation

molecule {
0 1
O 0.000000 0.000000 6.000000
H 0.000000 1.431500 4.890600
H 0.000000 -1.431500 4.890600

0 2
O 0.000000 0.000000 0.000000
O 0.000000 2.503900 0.000000
H 0.000000 -0.424700 -1.839500
units bohr
symmetry c1

set {
reference uhf
scf_type df
basis cc-pVDZ


i have tried to run the above input file in psi4 for sapt analysis which i have got psi4 sample file. unfortunately, the ‘out’ file was showing error something like following…

/home/iball/psi4conda/lib/python2.7/site-packages/v2rdm_casscf/ loaded.

Memory set to 4.000 GiB by Python script.

An error has occurred python-side. Traceback (most recent call last):

File "<string>", line 67, in <module>

File "/home/iball/psi4conda/share/psi4/python/", line 446, in energy

wfn = procedures[‘energy’][lowername](lowername, molecule=molecule, **kwargs)

File "/home/iball/psi4conda/share/psi4/python/procedures/", line 2749, in run_sapt

raise ValidationError(‘SAPT requires requires &quot;reference rhf&quot;.’)

ValidationError: SAPT requires requires "reference rhf".

-please resolve my error in calculation.

What version of Psi4 are you using? Your traceback leads me to suspect the version you are using is rather old. Depending on how old it is, open-shell SAPT0 may not exist in the code.

The Psi4 which I am using is just downloaded and installed last weak from this site last 10 days back.


but i am unaware about the version of it…

please tell me the new version which support open shell sapt0

The information I’m looking for will be in the first six lines of the output file. If you’re using the latest official release, it should look something like

          Psi4: An Open-Source Ab Initio Electronic Structure Package
                               Psi4 1.3 release

                         Git: Rev {HEAD} 20e5c7e 


Just as I thought, you need to update your version of Psi. Upgrade to Psi 1.3, and you can do open-shell SAPT0. Get the latest version here. Let me know if that works!

Where did you find a link to that version of Psi? Something that old shouldn’t be on this site.

I don’t remember the version that I have downloaded but I am sure it was from this site
Thanks for your consistent reply and support for my each queries…

so, I’ll download the Psi4 1.3 version from the your link or the site.

Thank you

I downloaded the Psi 1.3 from the site, please tell me how will I upgrade my 1.0 version with 1.3.

Well, how did you install it? Once the path is set up correctly, typing psi4 on the command line should just use Psi4 1.3.

Ok, installation is over and I started my work about sapt analysis of rohf…I got proper output file…but in terminal it is showing
What it means?

Lori explained it here. You can ignore that message, or use the changes she suggested if that warning bothers you enough.

Anything else?

Nothing else…
Thank you

Marking the topic closed, then.

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