.. _alloy:

[Alloy]: Alloy structure
========================================

Definition of alloy pseudo-species. Each pseudo-species is defined by
a label followed by an equal sign and a block specifying constituting
alloy components along with their parameters.

----

spec-label =
    +--------------+-------+------------------------------------+
    |   Species1   | Conc1 | <Other component parameters>       |
    +--------------+-------+------------------------------------+
    |   Species2   | Conc2 | <Other component parameters>       |
    +--------------+-------+------------------------------------+
    |   ...        | ...   | ...                                |
    +--------------+-------+------------------------------------+
    |   SpeciesN   | ConcN | <Other component parameters>       |
    +--------------+-------+------------------------------------+

----

The concentrations of all components for a given pseudo-species must sum up to 1.

Component parameters are similar to site parameters of the `[Structure]` section
except for two alloy-specific parameters, namely CPA screening constants,
:math:`\alpha`, :math:`\beta`.

The defined pseudo-species can then be used in the `[Structure]` section in place
of a elemental species. The pseudo-species is referenced by its label as follows:
`${spec-label}`.


.. tabularcolumns:: |C|C|C|L|

+--------------------+------------------+----------+---------------------------------------------------------------+
| Parameter          |  Type            | Default  |  Description                                                  |
+====================+==================+==========+===============================================================+
| **psr**            | `<float>`        |   1.0    | Potential sphere radius in units of the average WS radius     |
+--------------------+------------------+----------+---------------------------------------------------------------+
| **mom**            | `<float>`        |   0.0    | Initial spin splitting or magnetic moment (`lsm_mode = fxm`)  |
+--------------------+------------------+----------+---------------------------------------------------------------+
| **lsm_mode**       | `<string>`       | **none** | Local spin moment mode: **none**, **fxm**, **dlm**, **lsf**   |
+--------------------+------------------+----------+---------------------------------------------------------------+
| **lsf_params**     | `<integer>`      |     3    | LSF effective dimension: 1, 2, or 3                           |
+--------------------+------------------+----------+---------------------------------------------------------------+
|    **al_scr**      | `<float>`        |   0.65   | CPA screening constant :math:`\alpha`                         |
+--------------------+------------------+----------+---------------------------------------------------------------+
|    **bet_scr**     | `<float>`        |    1.0   | CPA screening constant :math:`\beta`                          |
+--------------------+------------------+----------+---------------------------------------------------------------+