# TB2J_edit

TB2J_edit is a tool for modifying TB2J results. It allows you to post-process the exchange parameters calculated by TB2J, such as adding single-ion anisotropy, toggling DMI or anisotropic exchange, and symmetrizing the exchange parameters.

## Command Line Interface

The `TB2J_edit.py` command provides several subcommands:

### Load and Save

Simply load and save the results (useful for format conversion or checking if the file is valid).

```bash
TB2J_edit.py load -i TB2J_results/TB2J.pickle -o modified_results
```

### Set Single-Ion Anisotropy

Set the single-ion anisotropy (SIA) for specific atomic species.

```bash
# Set Sm anisotropy to 5 meV along z-axis
TB2J_edit.py set-anisotropy -i TB2J_results/TB2J.pickle -o modified_results -s Sm 5.0 -d "0 0 1" -m
```

*   `-s SPECIES K1`: Set the anisotropy constant `K1` for `SPECIES`. Can be used multiple times.
*   `-d "x y z"`: Set the direction of the anisotropy axis (default is [0, 0, 1]).
*   `-m`: Interpret `K1` in meV (default is eV).

### Toggle DMI and Anisotropic Exchange

Enable or disable Dzyaloshinskii-Moriya Interaction (DMI) or anisotropic exchange (Jani).

```bash
# Disable DMI
TB2J_edit.py toggle-dmi -i TB2J_results/TB2J.pickle -o modified_results --disable

# Enable Anisotropic Exchange
TB2J_edit.py toggle-jani -i TB2J_results/TB2J.pickle -o modified_results --enable

# Disable Isotropic Exchange
TB2J_edit.py toggle-exchange -i TB2J_results/TB2J.pickle -o modified_results --disable
```

### Symmetrize Exchange

Symmetrize the isotropic exchange parameters based on a reference crystal structure. This is useful if the calculated J values slightly break symmetry due to numerical noise or if you want to enforce a higher symmetry (e.g., from a high-temperature phase).

```bash
TB2J_edit.py symmetrize -i TB2J_results/TB2J.pickle -S structure.cif -o modified_results
```

*   `-S STRUCTURE`: Path to the reference structure file (e.g., CIF, POSCAR).

### Remove Sublattice

Remove all magnetic interactions associated with a specific sublattice. This includes Single-Ion Anisotropy (SIA), Exchange (J), DMI, and Anisotropic Exchange involving atoms of the specified species.

```bash
TB2J_edit.py remove-sublattice -i TB2J_results/TB2J.pickle -o modified_results -s Sm
```

*   `-s SUBLATTICE`: The name of the sublattice (species symbol) to remove (e.g., 'Sm', 'Fe').

### Info

Show information about the TB2J results, including composition, number of magnetic atoms, and enabled interactions.

```bash
TB2J_edit.py info -i TB2J_results/TB2J.pickle
```

## Python API

You can also use the `TB2J.io_exchange.edit` module in your Python scripts.

```python
from TB2J.io_exchange.edit import load, set_anisotropy, set_sia_tensor, remove_sia_tensor, toggle_DMI, toggle_exchange, save

# Load results
spinio = load('TB2J_results/TB2J.pickle')

# Modify results
set_anisotropy(spinio, species='Sm', k1=5.0, k1dir=[0, 0, 1]) # k1 in eV

# Set full 3x3 SIA tensor
import numpy as np
tensor = np.diag([0.001, 0.002, 0.003]) # eV
set_sia_tensor(spinio, species='Sm', tensor=tensor)

toggle_DMI(spinio, enabled=False)
toggle_exchange(spinio, enabled=False)

# Save results
save(spinio, 'modified_results')
```

### Functions

*   `load(path)`: Load TB2J results from a pickle file.
*   `save(spinio, path)`: Save modified results to a directory.
*   `set_anisotropy(spinio, species, k1, k1dir)`: Set uniaxial single-ion anisotropy.
*   `set_sia_tensor(spinio, species, tensor)`: Set full single-ion anisotropy tensor.
*   `remove_sia_tensor(spinio, species)`: Remove single-ion anisotropy tensor.
*   `toggle_DMI(spinio, enabled)`: Enable/disable DMI.
*   `toggle_Jani(spinio, enabled)`: Enable/disable anisotropic exchange.
*   `toggle_exchange(spinio, enabled)`: Enable/disable isotropic exchange.
*   `remove_sublattice(spinio, sublattice_name)`: Remove interactions for a sublattice.
*   `symmetrize_exchange(spinio, atoms, symprec)`: Symmetrize exchange parameters.