ML OUTBLOCK: Difference between revisions

Revision as of 14:13, 20 March 2024

ML_OUTBLOCK = [integer]
Default: ML_OUTBLOCK = 1

Description: Output distance in number of steps for molecular-dynamics simulations with machine-learned force fields in prediction-only mode (ML_MODE = run).

Important: This tag is only available as of VASP.6.4.0. Unfortunately, the implementation of this feature was incomplete before VASP.6.4.3. in VASP versions prior to 6.4.3 there was still substantial remaining per-time-step output, in particular in vasprun.xml and vaspout.h5.

By default VASP writes all results at every molecular-dynamics step (ML_OUTBLOCK = 1). However, this may become inefficient when running long trajectories in production runs with a machine-learned force field in prediction-only mode (ML_MODE = run). This is particularly true if the force field supports the fast execution mode, i.e., refitting was performed with ML_MODE = refit. Then, depending on the system size, writing output each time step may hinder performance, cause heavy I/O load and create unnecessary large files. In order to circumvent these problems ML_OUTBLOCK = n instructs VASP to write screen and file output only every n time steps.

In order to further increase the efficiency, calculation and output of pair-correlation functions can be completely switched off by setting ML_OUTPUT_MODE = 0.

Warning: This tag will potentially override defaults and INCAR values of NBLOCK! NBLOCK will be automatically set to the maximum of ML_OUTBLOCK and NBLOCK.

@@ Line 2: / Line 2: @@
 {{TAGDEF|ML_OUTBLOCK|[integer]|1}}
-Description: Output distance in number of steps of the molecular-dynamics results for {{TAGO|ML_MODE|run}} within the machine learning force fields.
+Description: Output distance in number of steps for molecular-dynamics simulations with machine-learned force fields in prediction-only mode ({{TAGO|ML_MODE|run}}).
-{{NB|mind|This tag is only available as of VASP.6.4.0.}}
+{{NB|important|This tag is only available as of VASP.6.4.0. Unfortunately, the implementation of this feature was incomplete before VASP.6.4.3. in {{VASP}} versions prior to 6.4.3 there was still substantial remaining per-time-step output, in particular in {{FILE|vasprun.xml}} and {{FILE|vaspout.h5}}.}}
 ----
-By default the code writes all results at every molecular-dynamics step ({{TAGO|ML_OUTBLOCK|1}}).
+By default {{VASP}} writes all results at every molecular-dynamics step ({{TAGO|ML_OUTBLOCK|1}}). However, this may become inefficient when running long trajectories in production runs with a machine-learned force field in prediction-only mode ({{TAGO|ML_MODE|run}}). This is particularly true if the force field supports the fast execution mode, i.e., refitting was performed with {{TAGO|ML_MODE|refit}}. Then, depending on the system size, writing output each time step may hinder performance, cause heavy I/O load and create unnecessary large files. In order to circumvent these problems {{TAGO|ML_OUTBLOCK|n}} instructs {{VASP}} to write screen and file output only every <code>n</code> time steps.
-{{TAGO|ML_OUTBLOCK|1|op=>}} becomes only relevant for the fast force fields (refitting with {{TAGO|ML_MODE|refit}}), because then the calculation time of the force field is of the same order as the time required for the output to all necessary files.
-To additionally increase the efficiency, calculation and output of pair-correlation functions can be completely switched off by setting {{TAGO|ML_OUTPUT_MODE|0}}. {{NB|warning|This tag will potentially override defaults and {{FILE|INCAR}} values of {{TAG|NBLOCK}}! {{TAG|NBLOCK}} will be automatically set to the maximum of {{TAG|ML_OUTBLOCK}} and {{TAG|NBLOCK}}.}}
+In order to further increase the efficiency, calculation and output of pair-correlation functions can be completely switched off by setting {{TAGO|ML_OUTPUT_MODE|0}}. {{NB|warning|This tag will potentially override defaults and {{FILE|INCAR}} values of {{TAG|NBLOCK}}! {{TAG|NBLOCK}} will be automatically set to the maximum of {{TAG|ML_OUTBLOCK}} and {{TAG|NBLOCK}}.}}
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