.. _dmftloop:

Building DMFT calculations
==========================

TRIQS includes all basic ingredients to write DMFT computations:
Green's functions and impurity solvers. The self-consistency condition is assembled
from these ingredients, using the basic operations on Green's function (arithmetic
operations, slicing, ...).

There is no `general` DMFT computation class that would handle all cases, just the
bricks to build them easily. Here's an example:

Plain-vanilla DMFT: the Bethe lattice
-------------------------------------

Here is a complete computation of a single-site DMFT on a Bethe lattice
:download:`[script] <dmft.py>`:

.. literalinclude:: dmft.py

The solver has been discussed above, so let us just emphasize
that the DMFT loop itself is `polymorphic`: it would run as well with
any other solver, as long as it provides `G0_iw` and `G_tau` attributes.
Even if here the self-consistency condition is very simple,
this property would still be true in more complex cases.

This run generates a file :file:`single_site_bethe.h5` containing the Green's function
at every iteration. You can plot them to see the convergence on the solver:

.. plot:: guide/dmft_plot.py
    :scale: 70