Input File

input.h5 is written by green-mbtools and read by green-mbpt. This page describes the GREEN 1.0 input-file contract. Shapes use the shared notation.

The root attribute __green_version__ records the version of green-mbtools that wrote the file.

/
├── Cell
├── params/{nao,nso,ns,nel_cell,nk,NQ}
├── HF/{Fock-k,S-k,H-k,Energy,Energy_nuc,madelung,Nk,nk,mo_energy,mo_coeff}
├── mulliken/{Zs,last_ao}
├── symmetry/k/{mesh,mesh_scaled,nk,ink,nk_list,ibz2bz,bz2ibz,weight_ibz,tr_conj,n_stars,stars,k_sym_transform_ao}
├── symmetry/q/{mesh,mesh_scaled,nq,inq,ibz2bz,bz2ibz,weight_ibz,tr_conj,n_stars,stars,k_sym_transform_j2c,k_sym_transform_p0}
├── symmetry/pairs/{kpair_idx,conj_pairs_list,trans_pairs_list,kpair_irre_list,num_kpair_stored}
├── orthogonalization/{X_k,X_inv_k}        (optional)
└── high_symm_path/{k_mesh,r_mesh,Hk,Sk,xpath,special_points,special_labels} (optional)

File identity and dimensions

Mean-field data

The matrix axes are ordered as spin channel, full k-point, row orbital, column orbital, and, where present, real/imaginary component.

GREEN uses atomic-unit conventions, but these datasets do not store unit attributes. Fock-k, H-k, and mo_energy are in Hartree. S-k, symmetry transforms, fractional meshes, and lattice-vector coefficients are dimensionless. Absolute /symmetry/k/mesh and /symmetry/q/mesh coordinates are in Bohr^-1.

Mulliken metadata

Here natom is the number of atoms in the cell or molecule.

K-point symmetry and reconstruction

The k-point hierarchy describes the full Brillouin-zone mesh, its irreducible representatives, and transformations used to reconstruct matrix-valued quantities.

For a matrix-valued quantity, reconstruct a full-grid value from its representative as

When tr_conj[k] is true, complex-conjugate the resulting matrix. Molecular inputs retain this hierarchy as a one-Gamma-point identity case.

Advanced symmetry metadata

The q mesh is the unique wrapped set of k-point differences. It therefore need not equal the k mesh.

The pair tables index the triangular set of full-grid k-point pairs and its symmetry reductions.

Optional orthogonalization

The /orthogonalization group is present only when --orth is not none.

For X2C, the analogous transformations use spin-orbital dimensions rather than the AO-only dimensions shown above.

High-symmetry-path input

The /high_symm_path group is created only when high-symmetry-path evaluation is requested. Its path-dependent lengths follow the selected path. See also the high-symmetry-path output.

xpath is the ASE-derived inverse-angstrom coordinate for each of the nhs_k path points. Here n_special is the number of labeled special points on the selected path; special_points and special_labels have one value per such point.

Reading complex data with Python

Fock-k, S-k, and H-k use a final length-two real/imaginary axis. Other input datasets, including symmetry transforms and some mo_coeff values, may instead use HDF5 compound complex values.

import h5py

with h5py.File("input.h5", "r") as data:
    nk = int(data["params/nk"][()])
    nso = int(data["params/nso"][()])
    stored = data["HF/Fock-k"][...]
    fock = stored[..., 0] + 1j * stored[..., 1]

print(nk, nso, fock.shape)