# The output files for the nep executable

Jump to navigation
Jump to search
## The

## The

## The

## The

## The

## The

## Contents

## Brief descriptions

- There are a number of output files for the
`nep`

executble. They have fixed names as given below.

- The
`descriptor.out`

file will be generated in the beginning of the training and will not be updated later.

- All the other files will be updated every 100 generations during the training.

- Except for the
`nep.txt`

file, all the other files contain pure numbers (no text) in matrix form.

- All the files are plain text files (not binary ones).

## Conventions

- [math]N_{\rm c}[/math]: number of configurations in the training set.
- [math]N[/math]: total number of atoms in the training set.
- [math]N_{\rm des}[/math]: dimension of the descriptor.
- [math]n_{\rm max}^{\rm R}[/math]: the Chebyshev expansion order for the radial components of the descriptor.
- [math]n_{\rm max}^{\rm A}[/math]: the Chebyshev polynomial expansion order for the angular components of the descriptor.
- [math]l_{\rm max}[/math]: the Legendre polynomial expansion order for the angular components of the descriptor.

## The `descriptor.out`

file

- This file contains the descriptor components of all the atoms in the training set. It will be created in the beginning of the training.

- This file has a matrix of data with [math]N[/math] rows and [math]N_{\rm des}[/math] columns.

- The order of the atoms (from the first to the last row) is the same as that in the
`train.in`

input file.

- The order of the descriptors (from the first to the last column) is as follows:
- The first [math]n_{\rm max}^{\rm R}+1[/math] items correspond to the radial components of the descriptor.
- The next [math](n_{\rm max}^{\rm A}+1)l_{\rm max}[/math] items correspond to the angular components of the descriptor. These items are arranged such that the first [math]n_{\rm max}^{\rm A}+1[/math] items with [math]l=1[/math] come first, then followed those with [math]l=2[/math], and so on.

## The `loss.out`

file

- This files contains the various loss functions during the training, with an interval of 100 generations.

- Each row of this file reads:

gen L_t L_1 L_2 L_e L_f L_v

Here:

`gen`

is the current generation (step).`L_t`

is the total loss function (sum of the other loss functions).`L_1`

is the loss function related to the [math]\mathcal{L}_1[/math] regularization.`L_2`

is the loss function related to the [math]\mathcal{L}_2[/math] regularization.`L_e`

is the loss function related to the energies.`L_f`

is the loss function related to the forces.`L_v`

is the loss function related to the virials.

## The `nep.txt`

file

- This is the NEP potential file generated by the training. It can be used by the
`gpumd`

executable to run MD simulations.

- The user does not need to understand the contents of this file. In case the user wants to understand the contents, please refer to the source code.

## The `energy.out`

file

- This file contains the predicted energies versus the training energies.

- There are 2 columns. The first column gives the energies (in units of eV/atom) calculated from NEP. The second column gives the corresponding energies (in units of eV/atom) from
`train.in`

.

- Each row corresponds to one configuration in
`train.in`

, with the same order.

## The `force.out`

file

- This file contains the predicted forces versus the training forces.

- There are 6 columns. The first three columns are the [math]x[/math], [math]y[/math], and [math]z[/math] force components (in units of eV/A) from NEP. The last three columns are the corresponding forces (in units of eV/A) from
`train.in`

.

- Each row corresponds to one atom in
`train.in`

, with the same order.

## The `virial.out`

file

- This file contains the predicted forces versus the training forces.

- There are 2 columns. The first column gives the virials (in units of eV/atom) calculated from NEP. The second column gives the corresponding virials (in units of eV/atom) from
`train.in`

. The number of rows is [math]6N_{\rm c}[/math]. The first [math]N_{\rm c}[/math] rows correspond to the [math]xx[/math] component of the viral in the same order as the energy data in`energy.out`

, followed by the [math]yy[/math], [math]zz[/math], [math]xy[/math], [math]yz[/math], and [math]zx[/math] components.