initialization in yambo 4.0.2

You can find here problems arising when using old releases of Yambo (< 5.0). Issues as parallelization strategy, performance issues and other technical aspects.

Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano, Conor Hogan

Locked
caowd
Posts: 22
Joined: Mon Jan 20, 2014 4:13 am

initialization in yambo 4.0.2

Post by caowd » Thu Mar 17, 2016 2:04 pm

Dear all

There are lots of Kpoints in my recent calculations and I find that if I use the yambo in 4.0.2 version, there could be an error like

"NetCDF: One or more variable sizes violate format constraints"

After I checked the files in the SAVE/ directory, I have found that the file ndb.kindx is too large.

However, if I switch to yambo 4.0.1 version, the error disappears. And for the ndb.kindx in the SAVE/ directory, there are two fragments "ndb.kindx_fragment_#".

I think there may be two possible reasons.
1. the netcdf which yambo in the newer version uses is different from that used previously
2. the yambo in the newer version needs more options like "yambo -xxx" to obtain the fragments of ndb.kindx
Wen-Dong Cao
Candidate for Ph.D
Department of Physics
Group of Condensed Material Theory
Tsinghua University
Beijing P.R.China
+86 010 62772784

User avatar
Daniele Varsano
Posts: 4209
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: initialization in yambo 4.0.2

Post by Daniele Varsano » Thu Mar 17, 2016 2:25 pm

Dear Wen-Dong Cao,
this is because netcdf admits a fixed number of variables. May be the number of variables admitted can be changed when compiling netcdf libraries.
Anyway, as you said, you can overcome the problem by fragmenting the databases. This is now done by adding the io verbosity when building up the input file:

Code: Select all

yambo -i -V io
and setting:

Code: Select all

DBsFRAGpm= "+QINDX"            # [IO] Space-separated list of +DB to be FRAG and -DB NOT to be FRAG. DB=(DIP,X,W,HF,COLLS,K,BS,QINDX,
Please note the "+" sign.

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

caowd
Posts: 22
Joined: Mon Jan 20, 2014 4:13 am

Re: initialization in yambo 4.0.2

Post by caowd » Fri Mar 18, 2016 7:24 am

Dear Daniele

I have changed the input file as you suggested and it indeed works now. :D

Thank you very much.


Best Wishes.
Wen-Dong Cao
Candidate for Ph.D
Department of Physics
Group of Condensed Material Theory
Tsinghua University
Beijing P.R.China
+86 010 62772784

Locked