by arjunvarmar » Mon Jun 18, 2018 11:50 am
Thank you so much for the reply.
Actually, I do not want to try out random qpts because, as a beginner, I just wanted to test whether the calculations I am doing is right or not.This is because of the fact that I cannot benchmark any of these random calculations.
For, homogeneous qpt grids, there are results available both in the "Abinit examples page" and also from literature which can be used for benchmarking. The ABINIT example page points to a reference "Ponce 2014" where the kpt grid is 6 x 6 x 6 and the qpt grid is 10 x 10 x 10. Further, in the Abinit example page, they have used qpt grids that are 4 x 4 x 4, 10 x 10 x 10, 20 x 20 x 20 etc. None of the qpt grids are subgrid or supergrid of the 6 x 6 x 6 kpt grid.
The ABINIT example page states that the kpt grid can be 6 x 6 x 6 but the qpt grid can be increased to obtain convergence. I would like to reproduce the results for these combinations since the ZPR shifts are also given in the ABINIT example page.
This is the direction I would like to proceed.
Your suggestion that the qpt grid has to be a subgrid of the kpt grid means that I will have to use very large kpt grid so that the qpt grid can also be large. Also, I will not have any benchmark results to compare my results with, since the results are not available in the ABINIT example page. I ran the standard input file in Abinit with kpt grid = 2 x 2 x 2 and
qpt grid = 4 x 4 x 4, which was running perfectly fine.
Later, I modified qpt grid to 2 x 2 x 2, which also gave results.
When we make kpt grids 4 x 4 x 4 and qpt grids 4 x 4 x 4, there are errors as shown in my first post.
That is, I am able to get results for two cases: i) 2 x 2 x 2 kpt and 2 x 2 x 2 qpt and ii) 2 x 2 x 2 kpt and 4 x 4 x 4 qpt.
But I am not getting results for 4 x 4 x 4 kpt and 4 x 4 x 4 qpt grids.
I am attaching input files which I had used for the working and nonworking cases, so so that you can see all the numbers that I used.
Please advise about how to proceed so that we can reproduce the examples as given in the ABINIT examples page.
Once again, thank you so much for your time and your suggestions.
Arjun
 Attachments

 tdepes_3.in
 This file is giving results. kpt 2 x 2 x 2 and qpt 2 x 2 x 2.
 (2.54 KiB) Downloaded 6 times

 tdepes_3.in
 This file is also giving results. kpt 2 x 2 x 2 and qpt 4 x 4 x 4.
 (2.54 KiB) Downloaded 6 times

 tdepes_3.in
 This file is not working. kpt 4 x 4 x 4 and qpt 4 x 4 x 4.
 (2.54 KiB) Downloaded 7 times