# Crystals

Crystal descriptions are immutable and may be loaded from XML or assembled
from unit-cell and atom-site values.

## Load a Crystal

```{eval-rst}
.. currentmodule:: lauelab.indexing

.. autofunction:: load_crystal
```

## Crystal Model

```{eval-rst}
.. currentmodule:: lauelab.indexing

.. autoclass:: Cell
   :members: in_angstrom

.. autoclass:: Atom

.. autoclass:: Crystal
   :members: crystal_system
```