starting YAMBO

[andrea marini]

I tried the EXCitaion software from ETSF sociesty, i installed it correctly but on running it is giving error
I know sir. it is not a platform for discussing the EXC problem, but i will be very thankful if you can help or give any forum link for EXC (i have already searched but culdnt find) where i could discuss the problem

Dear Dev, I am sorry but I am not an expert of EXC. Actually last time I have run it it was almost 10 years ago. So the easiest way is that you contact directly the authors of EXC that you can find here. There are not mail addresses, but Valerio is now in Grenoble and Francesco I think is back in Paris at the echole polytechnique. Check on the web and you should easily find their addresses.

Sorry, but I do not gave more informations to give you

[devsharma]

dear Andrea sir,
thanks for your information. Even we can find absorption, reflectance and EELS by yambo. I tried Yambo.
Sir, i tried with the GW example of Abinit for crystalline silicon and copied the KSS file in a folder and run
/home/dev/yem/yambo-3.2.1-r.448/bin/a2y -F tgw1o_DS1_KSS
i got a SAVE folder with the three files
s.db1 s.kb_pp s.wf
then in the same directory i run
/home/dev/yem/yambo-3.2.1-r.448/bin/yambo -F Inputs/01_init -J 01_init
and i got
r-01_int_setup in the same directory and ( db.gops and db.kindx in the SAVE folder )
then i used the command
/home/dev/yem/yambo-3.2.1-r.448/bin/yambo -F Inputs/02_RPA_no_LF -J 02_RPA_no_LF
and i got a file named 02_RPA_no_LF_setup
Sir now, how to plot the absorption spectrum. Sir, i think i am somewhere wrong in the third command. I have checked the 02_RPA_no_LF_setup and it is written there
CORE databases in .
Additional I/O in .
Communications in .
Input file is (none)
Report file is ./r-02_RPA_no_LF_setup
Job string is 02_RPA_no_LF

and in the last line it is there
.-Input file : (none)
and there i have not found any data, related to absorption.
Please help sir,
And secondly sir, on the link http://www.yambo-code.org/tutorials/tddft/index.php , on the right corner there is Tutorial pdf document] , i downloaded the PDF file which is of 26 pages. But i didnt found those 26 pages online. like on PDF file various link are given, how to open that links
like
file:///home/marini/Web/YAMBO/tutorials/tddft/lif_02_RPA_no_LF.html
. Can u give me link where these 26 pages manual is on web

Thanks
Take care
With regards
Dev
University of Delhi
INDIA

[andrea marini]

Sir, i tried with the GW example of Abinit for crystalline silicon and copied the KSS file in a folder and run
/home/dev/yem/yambo-3.2.1-r.448/bin/a2y -F tgw1o_DS1_KSS
i got a SAVE folder with the three files
s.db1 s.kb_pp s.wf
then in the same directory i run
/home/dev/yem/yambo-3.2.1-r.448/bin/yambo -F Inputs/01_init -J 01_init
and i got
r-01_int_setup in the same directory and ( db.gops and db.kindx in the SAVE folder )
then i used the command
/home/dev/yem/yambo-3.2.1-r.448/bin/yambo -F Inputs/02_RPA_no_LF -J 02_RPA_no_LF
and i got a file named 02_RPA_no_LF_setup
Sir now, how to plot the absorption spectrum. Sir, i think i am somewhere wrong in the third command.

Dev, please go step by step. First of all go here and download the tutorial tarball files. You do not need to create yourself the KSS file of Silicon, as the core dtabases are provided in the tarball files.
In the above command your are telling yambo to load the input file Input/02_RPA_no_LF. But you do not have that file. Input files are in the tarball files.
Then, please, follow step by step the instructions given on the tutorial web page. Scroll down to the end of the front page and click on each system to access the corresponding tutorial.

You will need some time to get used to the Yambo functionalities. Please take your time.

[myrta gruning]

Dear Dev

You may also give a look to http://www.yambo-code.org/doc/index.php (Quick Guided Tour, click on it to open the pdf).
As well note that yambo works like a shell command:
typing

Code: Select all

yambo -H

will provide the list of all available options (and what such an option means).

Also reading the main reference for Yambo http://www.yambo-code.org/counter/click.php?id=17 (in particular Sec. 5, 7) can help you to understand how yambo works and the the logic behind it.

Cheers,
Myrta

[devsharma]

Dear Andrea Sir,

Sir can you please tell me, what are the steps to be done to calculate the Absorption, Reflection and EELS for YVO4.
Sir,my group is totally experimental, and i usually read the forums and solve my problem becoz as such here is nobody who works in DFT and with whom i can have discussion.
I have learnt to use the Abinit and the PWscf.
Sir, is GW correction is necessary for the calculation of Absorption, EELS etc??? As i have seen in 3D_LiF/Abinit folder in tutorial tarball files, in 3D_LiF.in there is only two dataset. nothing i found in regard with of screening.
Sir , just guide a path , what are the steps to calculate these things.
i will be very thankful to you.
Dev
Univeristy of Delhi,
India

[Daniele Varsano]

Sir, is GW correction is necessary for the calculation of Absorption, EELS etc???

Dear Dev,
I'm not an expert on the system you are going to study, anyway GW corrections are needed if you want
to calculate Absorption and EELS in the GW+Bethe-Salpeter framework which is the most accurate, and it
is needed if your system presents excitonic effects. So you have to include screened electron-hole interaction
(Bethe-Salpeter equation). Otherwise, if such effect are negligible, you can calculate that quantities using
linear response in the RPA approximation, considering the local field effects, and I suggest you to start looking the optical properties at this level of theory. In order to do that, after initalising the databases (yambo -i to produce the input setup), you can
generate the input for the linear response calculation uising the (yambo -o c), next you should check when your spectra
reach the convergence adding bands in the non-interacting polarization function (BndsRnXd), in the size of the matrix
of the polarization function to invert (NGsBlkXd) and in the k-point sampling.
Please have a look to this part of the :documentation
In the LiF part of the tutorial you will find hints
to run RPA spectra.

Hope it helps,

Daniele