Density of states at Higher number of k points

[rishikanta_m]

Hi

I want to calculate the DOS for a structure of 4 atoms. So, I am doing the convergence test for the kpoints. My calculation crashes when the kpoints is 50x50x50. Is it due to lack of computational requirement. I am using 4 cores CPU with 32 GB RAM. Can you please help?

[fabien_tran1]

Hi,

With the command "top" you can check what RAM is used by the calculation. If this is close or more than 32 GB, then the calculation is likely to crash. It also depends if swapping is allowed on your machine. Some info here:
wiki/index.php/Memory_requirements
forum/viewtopic.php?f=4&t=18506

Besides, are you sure that you need such a dense k-mesh for the DOS?

[rishikanta_m]

Thank you for your suggestions and help.

Indeed, it requires a higher k-points sampling. The related papers are attached below:

https://journals.aps.org/prmaterials/ab ... s.3.034602
https://journals.aps.org/prmaterials/ab ... s.5.024602

[henrique_miranda]

I would recommend that you first try to perform the DOS calculations with coarser meshes for example 20x20x20 and 24x24x24 using the tetrahedron method ISMEAR=-4 or ISMEAR=-5
wiki/index.php/ISMEAR

If the results between these two different calculations still differ significantly (i.e. the number of k-points is still insufficient) I would ask you to please post the input files POSCAR, INCAR, POTCAR, and KPOINTS and OUTCAR so we can help you to reduce the memory usage in your calculation.

[rishikanta_m]

Thank you. I will try your suggestions