green¶
The one-body Green’s function
\(\langle c_{i\sigma_1}^{\dagger}c_{j\sigma_2}^{\phantom{\dagger}}\rangle\)
calculated by the wave-number space UHF method is exported in NumPy zip (npz) format.
Using the string (referred to as green_str) specified by the keyword green
in file.output section in the parameter file,
the filename is chosen as green_str.npz.
The data is bound to the key green. The data format is a numpy ndarray
with the layout ndarray(r, s, a, t, b), where
rdenotes a linearlinzed index of translation vector \([r_x\ r_y\ r_z]\), where the indices are packed intorbyr\(= r_z + N_z \cdot (r_y + N_y r_x)\).a,bdenote the indices of the orbitals \(\alpha, \beta\),s,tdenote the indices of the spins \(\sigma_1, \sigma_2\).
The output can be used as an initial configuration of the Green’s function
specified by the keyword initial in file.input section.
When the sublattice is considerd,
the Green’s function in unit of the sublattice is also stored with the key green_sublattice.
The indices of the data are regarded as those of the sublattice.
The following code is an example for reading the data from the output file.
import numpy as np
data = np.load("green.dat.npz")
green = data["green"]
