Add example for constructing flexible water model

Author: PicoCentauri

CONTRIBUTING.rst

@@ -49,6 +49,8 @@ files. If your example needs such data files, there are a few options available:
 - if the data files are small (few 10s of Kb) you may also include them in a
   ``data/`` folder within the example folder. A zip file will be generated that
   can be downloaded from the example page.
+- for a Python file that should not be rendered you can save it with a leading
+  underscore, e.g. ``_my_script.py``.
 
 .. _sphinx-gallery: https://sphinx-gallery.github.io/
 .. _RestructuredText: https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html

docs/requirements.txt

@@ -1,8 +1,10 @@
+setuptools
 sphinx
 sphinx-sitemap
 sphinx-design
 sphinx-gallery
 sphinx-toggleprompt
+sphinxcontrib-details-directive
 docutils
 furo
 chemiscope>=0.7

docs/src/conf.py

@@ -9,6 +9,7 @@
     "sphinx_design",
     "sphinx.ext.viewcode",
     "sphinx.ext.intersphinx",
+    "sphinxcontrib.details.directive",
     "sphinx_gallery.load_style",
     "chemiscope.sphinx",
 ]

examples/water-model/.gitignore

@@ -0,0 +1 @@
+*.pt

examples/water-model/README.rst

@@ -0,0 +1,5 @@
+Empircal water models
+=====================
+
+This example shows implemenetations of three and four point flexible water models and
+uses them to run molecular dynamics simulations of water.

examples/water-model/conf.gro

@@ -0,0 +1,12 @@
+channels:
+  - conda-forge
+dependencies:
+  - python=3.11
+  - pip
+  - pip:
+    - ase
+    - chemiscope>=0.7
+    - metatensor-torch
+    - metatensor-operations
+    - matplotlib
+    - torch-pme