SCAN meta-GGA functional

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Dear All.

Is there any activity going on to incorporate SCAN meta-GGA functional into NWChem?

Thank you very much.
Biswajit

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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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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

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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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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?

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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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