Adding notes in the documentation about the possibility to override t…

…he dimension and the boundaries.

docs/source/topics/data/parameters.md

@@ -58,6 +58,8 @@ The dictionary is separated into several nested dictionaries that control differ
     * ``box_tilt``: determines how [skewed the cell](https://docs.lammps.org/box.html) is, of great importance for triclinic systems (default: ``small``).
     * ``groups``: list with the names of the groups to be added. The names of the possible groups are generated by the list of possible kind names generated by the structure (default: skip parameter).
     * ``atom_style``: how the [atoms](https://docs.lammps.org/atom_style.html) are treated by the ``LAMMPS`` simulation.
+    * ``boundary``: allows to override the [boundary](https://docs.lammps.org/boundary.html) conditions as set by the AiiDA structure as they can be incompatible with what ``LAMMPS`` expects.
+    * ``dimension``: allows to override the [dimension](https://docs.lammps.org/dimension.html) as determined by the AiiDA structure as it is determined by the boundary conditions and this is not what ``LAMMPS`` expects.
 - ``potential``: parameters related to the potential describing the system:
     * ``potential_style_options``: extra parameters related to each of the possible pair styles (default: skip parameter).
     * ``neighbor``: sets the parameters affecting the construction of the [neighbor list](https://docs.lammps.org/neighbor.html) (default: skip parameter).