Overview¶
The green-mbtools is a python tool suite for Green’s-function-based many-body calculations implemented in the Green Software Package.
This package contains two main modules:
- mint (Mean-field INput generation Toolkit):
generates input files for Green/WeakCoupling using PySCF, ASE and SPGLib
- pesto (Post-processing Evaluation Software TOols):
provides access to various post-processing tools such as analytical continuation, wannier interpolation and Mulliken analysis.
Quickstart¶
To install the green-mbtools binary package simply execute
pip install green-mbtools
To get started with the post-processing of green-mbpt output, you can initialize the MB_post class using the
input, output and Matsubara grid (aka IR grid) files:
from green_mbtools.pesto import mb
import matplotlib.pyplot as plt
import numpy as np
if __name__ == "__main__":
# path to files
input_path = "path/to/input.h5"
output_path = "path/to/sim.h5"
ir_path = "path/to/ir/grid.h5"
# initialize the MB_post class
my_mb = mb.initialize_MB_post(output_path, input_path, ir_path)
# use my_mb to do other tasks
# e.g., Nevanlinna analytic continuation to get spectral function on real-axis
# with frequencies between -5 and 5 a.u. with 1001 grid points
# and broadening parameter of 0.01
freqs, Aw = my_mb.AC_nevanlinna(n_real=1001, w_min=-5.0, w_max=5.0, eta=0.01)
# trace over spin, k-points and orbitals
Aw_traced = np.einsum('wska -> w', Aw)
# plot the density of states
freqs_ev = freqs * 27.211 # convert frequency from a.u. to eV
plt.plot(freqs_ev, Aw_traced)
plt.show()
Features¶
The mbtools package comes with two sub-packages: mint and pesto. The mint sub-package contains utilities for the following tasks:
Generate input for Green/WeakCoupling.
Compute molecular/natural orbitals.
Mulliken analyasis based on symmetrical atomic orbitals.
On the other hand, the pesto sub-package, formerly known as the mbanalysis package, caters to:
Fourier transformation between real and reciprocal space
Fourier transformation between imaginary-time and Matsuabara frequency domain on intermediate representation (IR) grids (see Phys. Rev. B 101, 035144 (2020) for further details)
Wannier interpolation
Maxent analytical continuation using the external C++ library
Nevanlinna analytical continuation, based on Fei et.al. Phys. Rev. Lett. 126, 056402 (2021)
PES analytical continuation, based on Phys. Rev. B 107, 075151 (2023)
Caratheodory analytical continuation for complex valued matrices, implemented as a C++ library based on Fei et.al. Phys. Rev. B 104, 165111 (2021)