Yambo Community Forum

Dear Yambo developers:
I have a naive question about running Yambo. After creating the database, we need to run "yambo"
to set up db.gops and db.kindx files under SAVE. Suppose I did first the ground state
calculation with a small number of bands. Later, I want to include more bands in the
ground states, and set up the calculation for epsilon^-1. After I regenerate the s.wf and
s.db1, do I need to rerun "yambo"? Or can I recycle the previous db.gops and db.kindx
obtained with less bands? It seems to me that those files contain the information about the
shells of G vectors, but I don't know if they also depend on the number of bands.
Thanks
Deyu Lu

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Deyu Lu (Ph.D)

190 Chemistry Building
University of California, Davis
One Shields Avenue
Davis, CA 95616
Office phone: (530) 754-9663
Group Webpage: http://angstrom.ucdavis.edu/

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Dear Deyu Lu,
I suspect that Yambo will complain about inconsistencies in the header of the databases.
But I'm not sure, I never did it, why do you want to do this?? The Yambo inizialisation it
is not an heavy part and I suggest you to run it after having calculated your ground state
and the empty states you need for the epsilon.
Cheers,
Daniele

deyulu wrote: I have a naive question about running Yambo. After creating the database, we need to run "yambo"
to set up db.gops and db.kindx files under SAVE. Suppose I did first the ground state
calculation with a small number of bands. Later, I want to include more bands in the
ground states, and set up the calculation for epsilon^-1. After I regenerate the s.wf and
s.db1, do I need to rerun "yambo"? Or can I recycle the previous db.gops and db.kindx
obtained with less bands? It seems to me that those files contain the information about the
shells of G vectors, but I don't know if they also depend on the number of bands.

The exchange of databases between different SAVE folders is a delicate issue. By default it is not possible as the interfaces p2y and a2y assign to db1/wf/kb_pp databases a unique serial number (if you do yambo -D you will see it)
The S/N assigned to the core databases is then exported to ALL databases created. Most of these databases must respect the S/N. In the sense, if you overwrite the core databases yambo should automatically overwrite the database that do not respect the S/N. For example, db.gops and db.kindex are S/N dependent.

Thank you for the answer. I see the point.

Deyu