Tutorials
=========

On this page you will find links to a series of tutorials to help get you
started with Crispy. They are largely based on tutorials kindly provided by
`Amélie Juhin <http://www-ext.impmc.upmc.fr/~juhin>`_. The tutorials are in no
particular order, so you can start with the one that interests you.
Nevertheless, to make things easier to follow, have a look at the quick tour of
the interface below.

.. toctree::
    :maxdepth: 1

    ti_l23_xas.rst
    ni_ligand_field
    fe_spin_transition

Crispy's main window is divided in three parts: the plotting panel (1), the
logging panel (2), and the Quanty module panel (3), as shown in the figure
below.

.. figure:: assets/main_window_annotated.png
    :align: center
    :width: 80 %

The buttons located on the top of the plotting panel can be used to change the
properties of the plot, e.g zoom, scale, aspect ration, color etc. The
displayed plots can also be saved using various file formats.

The progress of the calculation and eventual errors are displayed in the
logging panel.

The panel of the Quanty module has a vertical tab structure. The *General
Setup* tab is located at the top, and will always be displayed when Crispy is
started. Here you can select the element, charge, and symmetry of the absorbing
site. The type of experiment, edge, temperature, and magnetic field can also be
selected here.

.. figure:: assets/experimental_conditions.png
    :align: center
    :width: 35 %

Depending on the type of experiment selected above, the panel below will
display a single tab with the parameters of the *Absorption Energy* for a XAS
calculation, or two tabs, *Incident Energy* and *Energy Transfer*, for a RIXS
calculation.

.. figure:: assets/absorption_energy.png
    :align: center
    :width: 35 %

The parameters include the energy range and the number of points for the
calculated spectrum. Both *Lorentzian* and *Gaussian* functions can be used to
broaden the spectrum. The *Lorentzian* broadening supports more complex input
values. For example an energy dependent broadening can be specify by using two
FWHM values, one for lower energy part of the spectrum, and a second one for
the high energy part. This feature is only available for some of the available
edges. Additionally the energy for the transition point between the two FWHM
values can also be specified as a third parameter. This is by default the
middle of the absorption energy range. Finally, the wave and polarization
vectors can be specified.

At the bottom of the *General Setup* tab you can select the spectra to be
calculated.

.. figure:: assets/spectra.png
    :align: center
    :width: 35 %

In the *Hamiltonian Setup* tab you can change the parameters of the
semi-empirical model used in the calculation. The scale factors for the
Coulomb, exchange, and spin-orbit coupling integrals can be changed using a set
of three input boxes. Note that the scale factors are used to alter the values
of the Hartree---Fock integrals.

.. figure:: assets/scale_factors.png
    :align: center
    :width: 35 %

Below are two panels displaying the list of Hamiltonian terms and parameters.
The terms can be enabled using the tick box placed in front of the name.
Selecting the name of a term will display the parameters associated with it in
the panel below. Double-click on the *Value* or the *Scaling* column of a
parameter to change it.

.. figure:: assets/hamiltonian_parameters.png
    :align: center
    :width: 35 %

At the bottom of the panel is possible to specify the number of initial
Hamiltonian states to consider in the calculation. The maximum number is equal
to the number of states for the initial electronic configuration, e.g. 1 state
for a |d0| configuration, 10 states for a |d1| configuration etc. By default
the number of states considered is automatically determined based on the value
of Boltzmann factors at the selected temperature, i.e. only states which will
have a significant occupation at this temperature will be considered. Finally,
for multiconfigurational calculations it is possible to specify the number of
electronic configurations to consider.

.. figure:: assets/states_and_configurations.png
    :align: center
    :width: 35 %

Completed calculations are displayed in the *Results* tab. The plotting panel
will be automatically updated when the selected calculation changes.
Right-clicking will display a context menu with a list of possible actions,
e.g. saving, loading, removing etc.

.. figure:: assets/results.png
    :align: center
    :width: 35 %

At the bottom of the Quanty module panel and not part of the tab structure
present above, there are two buttons. They can be used to save the input file
in a different location and/or with a different name, and start the
calculation. Once the calculation starts the *Run* button will change into a
*Stop* button, which can be used at any time to interrupt Quanty's run.

.. figure:: assets/buttons.png
    :align: center
    :width: 35 %

.. |L2,3| replace:: L\ :sub:`2,3`\
.. |M4,5| replace:: M\ :sub:`4,5`\
.. |d0| replace:: d\ :sup:`0`\
.. |d1| replace:: d\ :sup:`1`\