mdsuite/transformations/momentum_flux.py
"""
MDSuite: A Zincwarecode package.
License
-------
This program and the accompanying materials are made available under the terms
of the Eclipse Public License v2.0 which accompanies this distribution, and is
available at https://www.eclipse.org/legal/epl-v20.html
SPDX-License-Identifier: EPL-2.0
Copyright Contributors to the Zincwarecode Project.
Contact Information
-------------------
email: zincwarecode@gmail.com
github: https://github.com/zincware
web: https://zincwarecode.com/
Citation
--------
If you use this module please cite us with:
Summary
-------
"""
import typing
import tensorflow as tf
from mdsuite.database.mdsuite_properties import mdsuite_properties
from mdsuite.transformations.transformations import MultiSpeciesTrafo
class MomentumFlux(MultiSpeciesTrafo):
"""Transformation to calculate the momentum flux."""
def __init__(self):
super(MomentumFlux, self).__init__(
input_properties=[mdsuite_properties.stress],
output_property=mdsuite_properties.momentum_flux,
scale_function={"linear": {"scale_factor": 4}},
)
def transform_batch(
self,
batch: typing.Dict[str, typing.Dict[str, tf.Tensor]],
carryover: typing.Any = None,
) -> tf.Tensor:
fluxes = []
for properties in batch.values():
stress = properties[mdsuite_properties.stress.name]
phi = tf.stack([stress[:, :, 3], stress[:, :, 4], stress[:, :, 5]], axis=2)
fluxes.append(tf.reduce_sum(phi, axis=0))
return tf.add_n(fluxes)