ML LFAST: Difference between revisions

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{{NB|mind|This tag is only available as of VASP.6.4.0}}
{{NB|mind|This tag is only available as of VASP.6.4.0}}
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This tag switches on the descriptors for the fast execution mode. To use the fast execution mode the force field first has to be refit with the fast descriptors. As usual, the resulting {{TAG|ML_FFN}} has to be copied to {{TAG|ML_FF}} and the fast code will be automatically run in production mode runs by setting ({{TAG|ML_MODE}}=RUN or {{TAG|ML_ISTART}}=2).
This tag switches on the descriptors for the fast execution mode. To use the fast execution mode the force field first has to be refit with the fast descriptors. This is done by setting {{TAG|ML_MODE}} = ''REFIT'', which will automatically set {{TAG|ML_LFAST}} = ''.TRUE.''. As usual, the resulting {{TAG|ML_FFN}} has to be copied to {{TAG|ML_FF}} and the fast code will be automatically run in production mode runs by setting {{TAG|ML_MODE}} = ''RUN''.
 
To retrain the force field set the following:
*{{TAG|ML_MODE}}=REFIT (this will automatically set the fast mode)
or
*{{TAG|ML_LFAST}}=.TRUE.
*{{TAG|ML_ISTART}}=4


The speedup of the fast method compared to the regular method is increasing with increasing number of local reference configurations.
The speedup of the fast method compared to the regular method is increasing with increasing number of local reference configurations.

Revision as of 14:34, 31 March 2023

ML_LFAST = [logical]
Default: ML_LFAST = .FALSE. 

Description: This tag switches on the descriptors for refitting in the fast execution mode within machine learning force fields.

Mind: This tag is only available as of VASP.6.4.0

This tag switches on the descriptors for the fast execution mode. To use the fast execution mode the force field first has to be refit with the fast descriptors. This is done by setting ML_MODE = REFIT, which will automatically set ML_LFAST = .TRUE.. As usual, the resulting ML_FFN has to be copied to ML_FF and the fast code will be automatically run in production mode runs by setting ML_MODE = RUN.

The speedup of the fast method compared to the regular method is increasing with increasing number of local reference configurations.

It should be noted that in the fast version no Bayesian error estimation is available.

ML_LFAST must be used with ML_IALGO_LINREG>1.

Since the calculation time of the fast version is of the same order of magnitude as the timing for the output of the molecular-dynamics results, we advise decreasing the output frequency for molecular dynamics by the tag ML_OUTBLOCK. Additionally, the calculation and output of the pair-correlation function can be suppressed by ML_OUTPUT_MODE=0 as default.

Related tags and articles

ML_LMLFF, ML_MODE, ML_ISTART, ML_IERR, ML_OUTBLOCK, ML_OUTPUT_MODE