Yambo Community Forum

Hi,

I've been trying to reproduce the results for bulk Si in the paper Marini, A., Hogan, C., Gruning, M., Varsano, D., "yambo: An ab initio tool for excited state calculations", Computer Physics Communications, 180 (2009) 1392. Unfortunately I have as yet been unable to reproduce the results. On my system YAMBO is compiled without NETCDF support and as such I can't even check my calculations against the pre-computed structure supplied in the yambo compilation (since it is in NETCDF form only).

My aim has been this: to compute the bulk Si results found in the paper starting from the beginning at Abinit. I have tried almost every possible thing I can think of and still I am unable to reproduce the results published i the paper. In my attempts to do this I have examined the ecut value, the number of bands, the number of k-points and the lattice constant. None of these were significant enough to bring my outputs into line with the papers results. The only thing I did do that helped in any significant way was to change the way I defined the unit cell so that the rprim components were all positive for both the atoms (instead of having the second atom with negative x and y components). (Any hints as to why that made a significant difference would also be appreciated).

I have attached the Abinit files that I start from as well as all the files associated with the Yambo run. I based my Abinit file on the input Abinit file for the Solid_LiF tutorial with appropriate modifications.

Any help here would be most appreciated.

Hallo Daniel

Can you please edit the signature in your user profile adding your name and affiliation (so they will appear automatically at the bottom of all your posts)? I had to search the forum history for your name...

There are some differences in your abinit input: the cutoff (for the sample in the source is 15Ry), and the geometry, acell is 10.183 au
About changing the rprim causing changes in your output, I guess it corresponds to rotate the sample, so finally equivalent to changing the direction of the electric field.
Another think that I noticed, that may produce some difference is that in the sample there is no (n)s.kb_pp. So to reproduce the results you can try to remove it from the SAVE dir.
I hope this will help you. Let us know.

Final advice : try to compile with netcdf

Regards,
Myrta

Myrta,

Sorry for the slow response. It took me a while to get Yambo successfully installed with NetCDF. When I did the calculations again, there was no change with NetCDF as there was without. I did find the error though. Apparently I had been entering one number incorrectly. I was entering 0.2 instead of 0.02 into the BDmRange variable.

Thanks for the help.

Cheers,

Danno