Changelog

This document describes the main changes in TRIQS_HUBBARDI.

Version 3.0.0

hubbardI version 3.0.0 is a compatibility release for TRIQS version 3.0.0 that * introduces compatibility with Python 3 (Python 2 no longer supported) * adds a cmake-based dependency management

Version 2.2

This is a complete rewrite which is compatible to triqs 2.2. For solving the atomic problem the atom_diag function of triqs is used. The solve function now works completely similar to the cthyb solve function which ensures exchangeability between both solvers.

If you are moving from 1.4 to 2.2 this might help: The parts of a script in version 1.4

from pytriqs.applications.impurity_solvers.hubbard_I.hubbard_solver import Solver

# Init the Hubbard-I solver:
S = Solver( beta, l )

# set the atomic levels explicitly by matrix eal
S.set_atomic_levels( eal )

# solve and specify the interaction via U and J parameters
S.solve( U_int, J_hund )
transitions to the following in version 2.2
from triqs_hubbardI import *

# Init the Hubbard-I solver:
S = Solver( beta, gf_struct )

# set the interaction via an interaction Hamiltonian
U_sph = U_matrix( l, U_int, J_hund )
U_cubic = transform_U_matrix( U_sph, spherical_to_cubic(l, convention='') )
H = h_int_slater( spin_names, orb_names, U_cubic, map_operator_structure )

# set the non-interacting Green's function
S.G0_iw << inverse( S.Sigma_iw + inverse( S.G_iw ) )

# Solve the impurity problem specifying the interaction Hamiltonian
# the atomic levels are automatically set by the high frequency behavior of S.G0_iw
S.solve( h_int = H )
We can see two main changes:
  • The interaction in version 1.4 is given in terms of U_int and J_hund while it is given in terms of an arbitrary interaction Hamiltonian (triqs operator object) in version 2.2.
  • The atomic levels are set explicitly via eal in version 1.4 while they are extracted automatically from the non-interacting Green’s function S.G0_iw in version 2.2.

For a more detailed comparison compare the Ce example in the tutorial section of the dft_tools app and the Ce example in the example section here: DFT+DMFT example for Ce with VASP

Version 1.4

This version is only compatible to triqs 1.4. It comes with a fortran solver for the atomic problem.