The TB2J interface to OpenMX. TB2J is a open source python package for calculating the magnetic interaction parameters in Heisenberg models from DFT. It use the magnetic force theorem and take the local rigid spin rotation as a perturbation in the Green's function method.

The features include:

• Calculates parameters in Heisenberg model, including isotropic exchange, anisotropic exchange, Dyzanoshinskii-Moriya interaction.
• Can use the input from many DFT codes with Wannier90, e.g. Abinit, Quantum Espresso, Siesta, VASP, etc.
• Can use input from DFT codes with numerical orbitals from Siesta and OpenMX.
• Calculate magnon band structure from the Heisenberg Hamiltonian.
• Generate input for spin dynamics/Monte Carlo codes MULTIBINIT.
• Require only ground state DFT calculation.
• No need for supercells.
• Calculate magnetic interaction up to large distance.
• Minimal user input, which allows for a black-box like experience and automatic workflows.
• Versatile API on both the input (DFT Hamiltonian) and the output (Heisenberg model) sides.

For more information, see the documentation on https://tb2j.readthedocs.io/en/latest/ .

The section on TB2J-OpenMX can be found at https://tb2j.readthedocs.io/en/latest/src/openmx.html .

The link to TB2J: https://github.com/mailhexu/TB2J