SCAN meta-GGA functional

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3:36:10 PM PDT - Mon, May 14th 2018
Dear All. Is there any activity going on to incorporate SCAN meta-GGA functional into NWChem? Thank you very much. Biswajit

Forum Regular

8:11:30 AM PDT - Thu, May 24th 2018
Hi Biswajit, We have this in the development branch. You can get this from out github link https://github.com/nwchemgit/nwchem to invoke it use the following in your dft block xc scan

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11:07:32 AM PDT - Thu, Jul 18th 2019
Hi, Are you satisfied with the tests of the SCAN functional? Do you have any suggestion what numerical grid should be used with SCAN? Thank you, Biswajit

Forum Vet

6:32:13 PM PDT - Thu, Jul 18th 2019
Biswajit, We have performed extensive tests on the SCAN functional. https://github.com/nwchemgit/nwchem/issues/114 I would recommend fine (or larger: xfine, huge) grids. BSSE correction seem to be crucial for weakly bound systems (see tests in the github issue)

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12:07:57 PM PDT - Fri, Jul 19th 2019
Thank you. We have been looking at water clusters. We have been using xfine grid already. We are also using large basis set aug-cc-pv5z and experience suggests that BSSE will be almost negligible with that basis for DFT. However, how BSSE affects SCAN for water I don't know. The issue we are having is that SCAN is not giving the correct ordering among few isomers of water hexamers. The energy differences are very small within 1kcal/mol. I can provide more details of our calculation if needed. We will try BSSE. Also should we write to github or this forum for further issues?

Forum Vet

11:58:31 AM PDT - Mon, Jul 22nd 2019
Biswajit, My suggestion is to first, compute the BSSE correction, then file a github issue. I would also try the cc-pv5z basis (i.e. no aug-)

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