# The nep.in input file

## Brief descriptions

• This file specifies some hyper-parameters of the NEP potential.

## File format

• This file has the following fixed form:
cutoff              [cutoff]
n_max               [n_max]
l_max               [l_max]
num_neurons1        [num_neurons1]
num_neurons2        [num_neurons2]
batch_size          [batch_size]
maximum_generation  [maximum_generation]

• Do not modify the first column above.
• For each row, items within [ ] are to be filled by the user.

## An example

cutoff               4.0
n_max                6
l_max                4
num_neurons1         20
num_neurons2         0
batch_size           512
maximum_generation   100000

• Explanations:
• The cutoff distance of the potential is 4.0 A.
• The expansion order for the radial part is $n_{\rm max}=6$.
• The expansion order for the angular part is $l_{\rm max}=4$.
• The number of neurons in the first hidden layer is 20.
• The number of neurons in the second hidden layer is 0. Therefore, we are using a single hidden layer here.
• The number of configurations used in one batch at one step is 512.
• The training will be carried out for $10^5$ generations.