Warning during yambo initialization

[202321070091]

Dear all,
When I completed the calculations in PWSCF and initialized the SAVE folder, warnings "[WARNING] Impossible to define the grid unit vectors,[WARNING] Trying to expand the k-grid" and "[WARNING][RL indx]2 equivalent points in the rlu grid found,[RL indx] X grid is not uniform. Gamma point only." appeared. I tried to find a solution on the forum and entered "> yambo -i -V all" directly. After that, yambo couldn't be called. The last time I entered "> yambo -D >& /dev/null" and "> ls -lsrtR > LIST_log" directly, yambo couldn't be called either. Firstly, may I ask how I should address these warnings as they prevent me from proceeding with my calculations. Secondly, I was unable to call yambo twice because it had to be recompiled and installed before I could use it. May I ask if this is due to my operational issues or if yambo requires a paid service to use it? Looking forward to your answer.
Yours sincerely, WangQi.

[Daniele Varsano]

Dear WangQi,

Yambo is an open source code realised with GPL license so no paid service is needed and it is free to use!
Actually I do not understand what you mean when you say that Yambo cannot be called. What kind of message do you receive?
Once it is compiled you need just to run it provided you have set all the needed path for the linked library, in case you have a module system you need to load the module you used in phase of compilation before running the code. Remember that Yambo should be run in the directory containing the SAVE file generated by the p2y executable.

About your problem, it seems the code has problem to detect the k grid as uniform due to bravais lattice you are dealing with, you can try to perform the setup using an input file containing just:

Code: Select all

setup
NoDiagSC

If this, does not solve the issue you can try to accomodate your system in a simpler unit cell, if possibile.
If this is not possible and you need to stay with the cell you defined and NoDiagSC does not solve the issue you can solve the problem removing the symmetries in the QE calculation setting nosym=.true. in your QE input file.

Best,

Daniele

[202321070091]

Dear Daniele,
Thank you for your answer. I'm sorry, it was my English spelling problem. (1) The question I want to ask is that every time I directly enter the command ">yambo...", I cannot use YAMBO code for any command and need to reinstall and compile it before I can use it. I don't know if this problem is caused by my actions. (2) Regarding the issue of inconsistent K network, I executed the command "yambo - i" and added the parameter "NoDiagSC". Then deleted it/ SAVE/ndb *, executed "yambo - F yambo. in"(I'm not sure if this is correct) and ran yambo again, but still encountered "[WARNING] Impossible to define the grid unit vectors,[WARNING] Trying to expand the k-grid" and "[WARNING][RL indx]2 equivalent points in the rlu grid found,[RL indx] X grid is not uniform. Gamma point only." And what I calculated is already single cell. Finally, I checked my QE input file and added the parameter "nosym = .true.". Then, I continued to add the parameter "NoDiagSC" through "yambo - i" and ran yambo.in again, However, the warning still appeared. But I have a "X grid is uniform: yes" in the report file, does this mean that my second problem has been resolved and that I executed the command yambo. in correctly? If not, how should I handle it? And my yambo code has been reinstalled and compiled twice, is it because I entered commands starting with the “>” symbol directly?
Yours sincerely, WangQi.

[Daniele Varsano]

Dear WangQi,

if you have Uniform grid YES it means all is ok and you can go on with your calculation.
The symbol ">" it means the prompt and it should be not typed at all.

Best,
Daniele