Examples for the TB2J code. TB2J online doc: https://TB2J.readthedocs.io/en/latest/# TB2J github: https://github.com/mailhexu/TB2J TB2J forum: https://groups.google.com/g/tb2j
The examples with Wannier90 are in the Wannier directory. For these examples, first do a DFT ground state calculation, with e.g. ABINIT or VASP. The input of these DFT calculations are provided in the DFT directory. Then do a Wannier90 Calculation, of which the input are also in the DFT directory. The Wannier90 outputs are in the Wannier90 directory. With these files, run the command in getJ.sh to get the TB2J results.
SrMnO3 cubic structure with PBEsol+U , U(Mn)=3eV, 5atom cubic structure with FM state. In the Wannier directory, run get_J.sh to compute the exchange parameters.
SrMnO3 cubic structure with PBE+U , U(Mn)=3eV, 5atom cubic structure with FM state. In the DFT directory, run run.sh to run the full DFT-W90-TB2J calculation. In the Wannier directory, run get_J.sh to compute the exchange parameters from W90 output.
FeO structure with LDA+U , U(Fe)=4eV, with AFM state. In the DFT directory, run run.sh to run the full DFT-W90-TB2J calculation. In the Wannier directory, run get_J.sh to compute the exchange parameters from W90 output. Note: 1. the initial obital occupation is set in the input to break the orbital symmetry. 2. Fe 3d and 4s, O 2p orbital are in the W90 projections. The 4s orbital is to make the Fe 3d orbitals more localized.
bcc Fe. In the Wannier directory, run get_J.sh to compute the exchange parameters from W90 output. Note: The projected Wannier function is used instead of Maximally localized Wannier functions in order to get atomic centered WF's. The initial projectors are the s, p, and d orbitals. The first NN exchange values are much smaller than using Siesta LCAO basis, and from literature (KKR-Green).
SrMnO3 cubic structure, with PBE+U, U(Mn)=3eV in 10 atom supercell with G-AFM state. Note: in the DFT directory, the POTCAR file is not provided since it is proprietary, instead, the names of the paw potentials are in potcar.txt.
CrI3 monolayer. In the x, y, z directory, the DFT(VASP) and Wannier90 inputs are provided. Run VASP+Wannier90, and the get_J.sh in each directory, and then run the merge.sh script. Note: in the x y z directories, the POTCAR file is not provided since it is proprietary,
bcc cubic structure, calculated with PBE. run the getJ.sh command in the DFT directory.
hcp Co structure, calculated with PBE, with spin-orbit coupling. run the getJ.sh command in the DFT directory.
BiFeO3 R3c structure. First do the calculation for rotated structures (BiFeO3_x, BiFeO3_y, BiFeO3_z). Run the getJ.sh in each of these subdirectories to the the TB2J_result for each. Then run the merge.sh script to get the merged result. Note: the DFT hamiltonian files (siesta.nc) are not included because the files are too large. Run siesta in the DFT directory to get them.
bcc cubic structure, calculated with PBE. run the getJ.sh command.