diff --git a/Docs/source/burn_cell.rst b/Docs/source/burn_cell.rst
index 125ef8ed6..4ffb903e6 100644
--- a/Docs/source/burn_cell.rst
+++ b/Docs/source/burn_cell.rst
@@ -139,7 +139,7 @@ choice of network.
    network or integrator.
 
 
-To run the code, enter the burn_cell directory and run::
+To run the code, in the ``burn_cell`` directory run::
 
    ./main3d.gnu.ex inputs
 
diff --git a/Docs/source/eos_cell.rst b/Docs/source/eos_cell.rst
new file mode 100644
index 000000000..ff7fc9455
--- /dev/null
+++ b/Docs/source/eos_cell.rst
@@ -0,0 +1,72 @@
+************
+``eos_cell``
+************
+
+.. index:: eos_cell
+
+``eos_cell`` simply calls the equation of state on an input density, temperature,
+and composition, and then outputs the full thermodynamic state.  This is mainly
+used to understand the thermodynamics one might encounter in a simulation
+when using a particular EOS.
+
+Getting Started
+===============
+
+The ``eos_cell`` code is located in
+``Microphysics/unit_test/eos_cell``.  An inputs file which sets the
+default parameters for your thermodynamic state is needed to run the
+test.
+
+Setting the thermodynamics
+--------------------------
+
+The parameters that affect the thermodynamics are:
+
+* ``unit_test.density`` : the initial density
+
+* ``unit_test.temperature`` : the initial temperature
+
+* ``unit_test.small_temp`` : the low temperature cutoff used in the equation of state
+
+* ``unit_test.small_dens`` : the low density cutoff used in the equation of state
+
+The composition can be set in the same way as in ``burn_cell``, either
+by setting each mass fraction explicitly via the parameters,
+``unit_test.X1``, ``unit_test.X2``, ..., or forcing them to be all
+equal via ``unit_test.uniform_xn=1``.
+
+
+Building and Running the Code
+=============================
+
+The code can be built simply as:
+
+.. prompt:: bash
+
+   make
+
+.. note::
+
+   Even though there are no reactions, a network is still required,
+   and can be set via the ``NETWORK_DIR`` build variable.  By default,
+   the ``aprox13`` network is used.
+
+   The network choice serves only to set the composition, and a
+   ``general_null`` network may also be used.
+
+The build process will automatically create links in the build
+directory to any required EOS table.
+
+To run the code, in the ``eos_cell`` directory run::
+
+   ./main3d.gnu.ex inputs_eos
+
+where ``inputs_eos`` is the provided inputs file.  You may edit the
+thermodynamic state in that file prior to running.
+
+
+Output
+======
+
+All output is directed to ``stdout`` and simply lists the entries in the
+full ``eos_t`` datatype.
diff --git a/Docs/source/one_zone_tests.rst b/Docs/source/one_zone_tests.rst
index f77ef68c5..fa4a4c906 100644
--- a/Docs/source/one_zone_tests.rst
+++ b/Docs/source/one_zone_tests.rst
@@ -11,3 +11,4 @@ have analysis scripts, which we describe in the next sections.
    :hidden:
 
    burn_cell.rst
+   eos_cell.rst