[CP2K-user] [CP2K:22151] Re: Choice of RI basis set fo RPA calculation of argon dimer

[Frederick Stein]

Dear Riccardo,
You need to use the structure "BASIS_SET RI_AUX <basis set name>" to 
specify the RI-basis sets 
(see https://manual.cp2k.org/trunk/methods/post_hartree_fock/mp2.html).
Best,
Frederick

Riccardo Pezzetta schrieb am Mittwoch, 1. April 2026 um 16:16:58 UTC+2:

> Dear CP2K community,
> I am trying to calculate the binding energy of the argon dimer using RPA. 
> I used the basis set TZV2P-MOLOPT-PBE-GTH-q8 from the file BASIS_MOLOPT_UZH 
> with auxiliary basis set RI_85_7_6_5_5_0_0_0_8.0e-08 from the 
> file BASIS_RI_MOLOPT:
> BASIS_SET TZV2P-MOLOPT-PBE-GTH-q8
> BASIS_SET RI_AUX RI_85_7_6_5_5_0_0_0_8.0e-08
>
> With this basis I get -17.9 meV as binding energy. Then I tried to remove 
> RI_AUX in front of the auxiliary basis set:
> BASIS_SET TZV2P-MOLOPT-PBE-GTH-q8
> BASIS_SET RI_85_7_6_5_5_0_0_0_8.0e-08
>
> With these parameters i read in the output file:
> Orbital Basis Set                  RI_85_7_6_5_5_0_0_0_8.0e-08TZV2P-MOLOPT-
> and
> RI Auxiliary Basis Set             Ar-RI-AUX-RI_85_7_6_5_5_0_0_0_8.0e-08TZV
>
> It seems that the program mixes the two basis sets, but I don't know how. 
> The result is -10.6 meV which is closer to the experimental value (which is 
> -12.3 meV) than the result I obtained writing RI_AUX in front of the 
> auxiliary basis set. Could anyone explain me what happens with this basis 
> mixing and tell me if the result based in this parameters is reliable? I 
> have attached to this message the input and output files.
> Thank you in advance.
> Kind regards,
>
> Riccardo Pezzetta
>

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/cp2k/d36d6535-d08d-4bd3-880f-d46f74336a78n%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20260401/240a2e49/attachment.htm>