EPW Forum

Dear Samuel, I further test the subroutine print_gkk and have the following findings. 1. If the calculations are performed across different computing nodes, the |g| are different each time even using the same number of processors. 2. If the calculations are performoed on a single computing node, the...

Dear Samuel, Thank you for clarifying the two different concepts of restart. My situation is weirder that three calculations for MgB2 with the same input give different |g|. These three runs generate three epwmatwp1 files. If I restart the three calculations (by setting epwread = .true. and so on) w...

Dear Andrei and Samuel, Thank you very much for your nice explanations. But I still have some confusions. Yes, now I understand that epf17 is stored in memory and not written to disk, and then |g| can not be directly calculated in a restart calculation. But as mentioned by Samuel in another post, we...

Dear Samuel, Thank you very much for the quick reply. I can not fully understand your answer. Since in a restart calculation, we can calculate e-ph coupling constant lambda, which is related to |g|. I guess that the array epf17 or epmatf should be stored in the normal calculation (am I right?). Beca...

Dear Samuel, Thank you for sharing the subroutine print_gkk. I have run this subroutine for MgB2 using the double-delta approximation. In my calculation, the coarse k/q-mesh, and fine k/q-mesh are all 6x6x6. I set three runs with same input, but very different |g| are obtained. I have checked that t...

Dear all, My compound has 32 atoms per unit cell. In my calculation the coarse k- and q-meshes are 4x4x4. 64 MLWFs is used. I have tried to use less MLWFs, but failed. The parameter eft_mem is set to false. The epb file can be written to disk successfully. But the "segmentation fault" erro...

Dear all, In subroutine selfen_phon_q(iq), the k-dependent phonon linewidth gamma_qv(k) is calculated. In each pool, gamma_qv(k)s corresponding to different k-points that belonging to this pool are added together. The k-points are also distributed among different pools. Thus subroutine mp_sum is cal...

Dear Dr. Samuel Ponc,

Thanks for your quick response! I have another newly posted question about how to gather datum among pools when k parallelization. Look forward to your reply! Thanks again!

Best wishes,
Miao Gao

Dear all, Recently, I test the parallel_q parameter using MgB2 with double-delta approximation. I find that the results are somehow different with that obtained with parallel_k. Basically, there are five problems. Could you please tell me how to fix these problems? Thanks in advance! (1) the coordin...

Dear Samuel,

Thank you very much for telling me this method. It works fine after further adding

CALL mp_bcast (noncolin, ionode_id, inter_pool_comm)
CALL mp_bcast (noncolin, root_pool, intra_pool_comm)

in ephwann_shuffle.f90 around Line 250.

Best,
Miao Gao