NBLOCK: Difference between revisions

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Description: After {{TAG|NBLOCK}}  ionic steps the pair-correlation function and the DOS are calculated
Description: After {{TAG|NBLOCK}}  ionic steps the pair-correlation function and the DOS are calculated
and the ionic configuration is written to the {{FILE|XDATCAR}}-file. It is recommended to leave  {{TAG|NBLOCK}} to 1, since the computational overhead to determine the DOS and pair correlation function is minimal. Only for  molecular dynamics simulations with many 1000 steps or machine learning, it might be expedient to increase {{TAG|NBLOCK}} to say 10 or even 100, to avoid large {{FILE|XDATCAR}}-files.
and the ionic configuration is written to the {{FILE|XDATCAR}}-file. It is recommended to leave  {{TAG|NBLOCK}} to 1, since the computational overhead to determine the DOS and pair correlation function is minimal. Only for  molecular dynamics simulations with many 1000 steps or machine learning, it might be expedient to increase {{TAG|NBLOCK}} to say 10 or even 100, to avoid large {{FILE|XDATCAR}}-files and the evaluation of the pair correlation function at every step.
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In addition
In addition

Revision as of 08:50, 2 June 2023

NBLOCK = [integer]
Default: NBLOCK = 1 

Description: After NBLOCK ionic steps the pair-correlation function and the DOS are calculated and the ionic configuration is written to the XDATCAR-file. It is recommended to leave NBLOCK to 1, since the computational overhead to determine the DOS and pair correlation function is minimal. Only for molecular dynamics simulations with many 1000 steps or machine learning, it might be expedient to increase NBLOCK to say 10 or even 100, to avoid large XDATCAR-files and the evaluation of the pair correlation function at every step.


In addition

  • NBLOCK controls how often the kinetic energy is scaled if SMASS=-1.
  • After KBLOCK*NBLOCK ionic steps the averaged pair correlation function and DOS are written to the files PCDAT and DOSCAR. The internal accumulators are reset, and after another KBLOCK*NBLOCK steps the new averaged quantities are written out.

Mind: The CPU costs for these tasks are quite small, so use NBLOCK=1, except when you apply machine-learned force fields. In that case, you might want to increase NBLOCK to 10 to 100 to decrease the computational load and the file size of the XDATCAR file.

Related tags and articles

PCDAT, DOSCAR, XDATCAR, KBLOCK

Examples that use this tag