totEnJ 0.1.2

# Heisenberg exchange and DMI from DFT-calculated supercell total energies

<i>**Tools for preparing magnetic supercells and extracting (anisotropic) exchange interaction and DMI from their total energies (calculated for instance by DFT).**</i>

` pip install totEnJ `

If you find this package useful, please cite [L. Vojáček*, J. M. Dueñas* _et al._, Nano Letters (2024)](https://pubs.acs.org/doi/10.1021/acs.nanolett.4c03029).

## Usage See the Jupyter notebooks in the ./examples folder.

## Heisenberg exchange

Calculate Heisenberg exchange (in-plane and out-of-plane, uniaxial anisotropy) from total energy of magnetic supercells.

<center><img src=”https://github.com/user-attachments/assets/32c171bd-507b-4916-8d4a-0f9ca817d598” alt=”exchange_total_energy” width=”600” /></center>

## DMI

Calculate Dzyaloshinskii-Moriya interaction coefficients to arbitrary neighbor from DFT total energy for a linear chain (for now) - many systems will be equivalent however.

• nice-to-have functions: - automatically decide what spin spirals to use for a given problem and construct the supercells (and MAGMOM tag) - choose along which unit cell vector

BSD 3-Clause License

Copyright (c) 2023, liborsold

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.