how to ucontract basis sets in NWChem ?

[Miro]

Dear experts,

is there a way in NWCHem to have fully uncontracted basis out of Gaussian basis sets ?

Thanks, Miro

[Edoardo Aprà]

At the present time, the user cannot uncontract a gaussian basis present in the NWChem input file.

One option, other than editing the file by hand, is to request the basis set from the website https://www.basissetexchange.org/

with a recipe similar to what described in

https://nwchemgit.github.io/Basis.html#how-to-use-basis-files-from-httpswwwbasissetexchangeorg-new-in-2019

Contrary to what described in the URL above, you would need to check the "Uncontract Segmented" box and un-check the “Uncontract General” box

[Miro]

Thanks, Eduardo,

I am using this trick to have fully compatible basis set for nonrelativistic and DK relativistic NWChem calculations :  having the same exponents.

Best, Miro

[Miro]

Dear Edoardo,

I downloaded decontracted basis set from bse (H_C_O_P.nmr-dkh-decontr.bas), I encountered basis set reading error , see attachments.

What am I doing wrong ?

  bas_tag_lib: failed to locate basis n_(tz2p) in file
 H_C_O_P.nmr-dkh-decontr.bas
 bas_tag_lib: no such basis available                   0

Miro

[Edoardo Aprà]

My suggestion is to copy the basis set file inside the input file, instead of using the file input option.

[Miro]

OK, so copying the basis set file content into the input file is the solution;

BTW,  among QA examples I see reading from the file, but this is only for SOECP calculations ?

nwchem_master/QA/tests/.grep 'file ' */*.nw
at2-sodft/at2-sodft.nw:At library "AVTZ-2c" file ./LIB_SOECPS/AVTZ-2c
at2-sodft/at2-sodft.nw:At library "ECP60MDF" file ./LIB_SOECPS/ECP60MDF
at2-sodft/at2-sodft.nw:At library "SO ECP60MDF" file ./LIB_SOECPS/SO_ECPMDF-6