ML IWEIGHT: Difference between revisions

From VASP Wiki
No edit summary
No edit summary
Line 4: Line 4:
----
----
The following cases for {{TAG|ML_FF_IWEIGHT}} are possible:
The following cases for {{TAG|ML_FF_IWEIGHT}} are possible:
*{{TAG|ML_FF_IWEIGHT}}=1: Unnormalized energy, force and stress training data are divided by the weights determined by the flags {{TAG|ML_FF_WTOTEN}} (eV/atom), {{TAG|ML_FF_WTIFOR}} (eV/Angstrom) and {{TAG|ML_FF_WTSIF}} (kBar), respectively.
*{{TAG|ML_FF_IWEIGHT}}=1: The unnormalized energies, forces and stress tensor training data are divided by the weights determined by the flags {{TAG|ML_FF_WTOTEN}} (eV/atom), {{TAG|ML_FF_WTIFOR}} (eV/Angstrom) and {{TAG|ML_FF_WTSIF}} (kBar), respectively.
*{{TAG|ML_FF_IWEIGHT}}=2: The training data are normalized by using their standard deviations. The averaging is done over whole training data. The normalized energy, forces and stress tensor are multiplied by {{TAG|ML_FF_WTOTEN}}, {{TAG|ML_FF_WTIFOR}} and {{TAG|ML_FF_WTSIF}}, respectively. In this case the flags {{TAG|ML_FF_WTOTEN}}, {{TAG|ML_FF_WTIFOR}} and {{TAG|ML_FF_WTSIF}} are unitless quantities.  
*{{TAG|ML_FF_IWEIGHT}}=2: The training data are normalized by using their standard deviations. The averaging is done over whole training data. The normalized energy, forces and stress tensor are multiplied by {{TAG|ML_FF_WTOTEN}}, {{TAG|ML_FF_WTIFOR}} and {{TAG|ML_FF_WTSIF}}, respectively. In this case the flags {{TAG|ML_FF_WTOTEN}}, {{TAG|ML_FF_WTIFOR}} and {{TAG|ML_FF_WTSIF}} are unitless quantities.  
*{{TAG|ML_FF_IWEIGHT}}=3: Same as {{TAG|ML_FF_IWEIGHT}}=2 but training data is divided into individual systems. The energy, forces and stress tensor for a system are normalized using the average of the standard deviations of each system in the training data.
*{{TAG|ML_FF_IWEIGHT}}=3: Same as {{TAG|ML_FF_IWEIGHT}}=2 but training data is divided into individual subsets.
The energies, forces and stress tensors for each subset are normalized using the average of the standard deviation of all subsets in the training data. The division into subsets is based on the name tag as given in the POSCAR file.  


'''Mind''': For {{TAG|ML_FF_IWEIGHT}}=2 and 3 the weights are unitless quantities used to multiply the data, whereas for {{TAG|ML_FF_IWEIGHT}}=1 they have a unit and are used to divide the data by them. All three methods provide unitless energies, forces and stress tensors.
'''Mind''': For {{TAG|ML_FF_IWEIGHT}}=2 and 3 the weights are unitless quantities used to multiply the data, whereas for {{TAG|ML_FF_IWEIGHT}}=1 they have a unit. All three methods provide unitless energies, forces and stress tensors, that are passed
to the regression.


== Related Tags and Sections ==
== Related Tags and Sections ==

Revision as of 05:48, 2 October 2020

ML_FF_IWEIGHT = [integer]
Default: ML_FF_IWEIGHT = 3 

Description: Flag to control the weighting of training data in the machine learning force field method.


The following cases for ML_FF_IWEIGHT are possible:

The energies, forces and stress tensors for each subset are normalized using the average of the standard deviation of all subsets in the training data. The division into subsets is based on the name tag as given in the POSCAR file.

Mind: For ML_FF_IWEIGHT=2 and 3 the weights are unitless quantities used to multiply the data, whereas for ML_FF_IWEIGHT=1 they have a unit. All three methods provide unitless energies, forces and stress tensors, that are passed to the regression.

Related Tags and Sections

ML_FF_LMLFF, ML_FF_WTOTEN, ML_FF_WTIFOR, ML_FF_WTSIF

Examples that use this tag