Yambo Community Forum

Dear Developers,
I tried to ypp -s b -n -V qp and ypp to
run for the band calculation with yambo-4-0-2
but it does not give me any output!!!
can you please help me with this problem?
I attached the input file.

Best regards

Dear Samaneh,

First remove the time-reversal.
1) Build the input with ypp -n, edit it in order to remove the t-reversal symmetry.
2) run ypp.
A FixSymm directory will be created.
3) Go into FixSymm dir and run the setup (yambo -i).
4) Create input for band interpolation (ypp -s b), edit it and eventually add the GfnQPdb variable if you want read qp corrections
5) Run ypp

Best,
Daniele

Dear Daniele,

Thank you.

Dear Daniele,
I did the same as :
1- ypp -n
2-ypp
3- cd tmp/.save/Fixsymm and yambo -i
4- cd tmp/.save/Fixsymm and ypp -s b
But no ypp.in was made in Fixsymm folder???
also I tried
1- ypp -n
2-ypp
3- cd Fixsymm and yambo -i
4- cd tmp/.save and ypp -s b and then ypp
but no outputfile will be created!!
Am I in the wrong way??

Dear Samaneh,

cd tmp/.save/Fixsymm and yambo -i

I do not know what it is that exactly. After having removed the TR symmetry you should have the FixSymm (note the capital S)
there in the main directory you are running yambo.
The FixSymm directory should contain a SAVE directory.
In the FixSymm directory you need to execute the setup (yambo -i and then yambo).
Next calculate the bands in FixSymm directory.

Best,
Daniele

Dear Daniele,

Thank you for your reply.
why should I run yambo in FixSymm dir, since I have done it before
in tmp/.save dir and I want to use this database in the ypp input file??
do you mean that first of all (before doing gw calculation) I should
remove timereversal symmetry by ypp -n and then go to the FixSymm
dir to do other calculations like gw (yambo) and then band calculation??

Dear Samaneh,
sorry but I cannot get your point. And I really do not know what do you have in the tmp/.save directory. Surely the directory is not created by Yambo.
In order to interpolates bands you need to remove the symmetries. So, in your main directory you run ypp when in your input file you tell yambo to remove directory (ypp -n). Yambo will crate a directory called FixSymm which contain a SAVE directory where wavefunctions and KS structure database are contained. These are the ones have the TR removed. Enter in FixSymm and initialize (yambo -i) and then yambo. This is needed to create the right indexes in *this* directory containing the SAVE with the TR removed. Yambo cannot know you run the setup and yambo in the previous dir, the database in the ./FIxSymm/SAVE are different from the previous one as you removed the symmetryes!!. Next always from this directory you run the ypp for the band interpolation. You can tell in the input where is the QP database you want to use for the interpolation, or copy it in the SAVE of the FixSymm directory.

Best,
Daniele

Dear Daniele,

Thank you for your previous reply.
I did all you said:
1: cd tmp/.save (where o.qp and yambo.in is generated)
2: run ypp -n (removing TR symmetry)
3: ypp
4: cd tmp/.save/FixSymm
5: ypp -s b -V qp
6: ypp
but still it does not generate any output in the FixSymm dir!!!
Can you please check the attached input file of ypp??

Best regards

Dear Samaneh,
A setup of the calculation is missing after step 4.
Once in FixSymm directory (yambo -i) and run yambo.
Next, ypp could complain when interpolating 30 bands, there is limit (20 if I'm not wrong), but you can interpolate many bands
running different inputs.

The variable BANDS_range it is not used anymore in yambo 4.0.x

Best,
Daniele

Dear Daniele,
Thanks for your reply.
I did also yambo -i and then yambo
(the generated yambo.in file include only
"setup # [R INI] Initialization")
and ypp -s b (with 10 bands) in the FixSymm dir and ypp
but the l_stderr file has an error!!!
Would yopu please check the attached files?

Best regards