Messages

1

General Questions and Answers / Re: abnormally long simulation time for a 2000-gold-atom system using DFTB

« on: June 1, 2021, 23:06 »

Yes. You are right. MPI parallelization may reduce the simulation time. But, I also found that by choosing the MultigridSolver, the simulation becomes much more efficient too particularly for large systems even on a single CPU core.

Thanks. 

2

General Questions and Answers / abnormally long simulation time for a 2000-gold-atom system using DFTB

« on: May 28, 2021, 19:13 »

Hi, all

    I am a new user of QuantumATK, and wanted to test its performance with DFTB.

    For a 576-gold-atom system, it takes 90 seconds on my desktop for each SCF cycle with a maximum memory usage of 1.8GB.

    While for a 2304-gold-atom system, it takes several hours for each SCF cycle with a maximum memory usage of 14.2 GB.

    Because my desktop is equipped with 32GB memory, the memory usage should not be an issue. But this huge difference on simulation time upon a moderate increase of system size is hard to understand.

   Enclosed please find my input files for both the 576-atom and 2304-atom systems.

    Please let me know if any change is needed on my input file to accelerate the 2304-atom simulation using DFTB.

   Thanks.

Hanning