diff --git a/README.md b/README.md
index e9b6ad43..c1e67a06 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,10 @@ or directly from GitHub:
```sh
python -m pip install "optimas[all] @ git+https://github.com/optimas-org/optimas.git"
```
-Make sure `mpi4py` is available in your environment before installing optimas. For more details, check out the full [installation guide](https://optimas.readthedocs.io/en/latest/user_guide/installation_local.html). We have also prepared dedicated installation instructions for some HPC systems such as
+
+If you intend to run Optimus with an MPI Runner, make sure `mpi4py` is available in your environment before installing optimas.
+
+For more details, check out the full [installation guide](https://optimas.readthedocs.io/en/latest/user_guide/installation_local.html). We have also prepared dedicated installation instructions for some HPC systems such as
[JUWELS (JSC)](https://optimas.readthedocs.io/en/latest/user_guide/installation_juwels.html),
[Maxwell (DESY)](https://optimas.readthedocs.io/en/latest/user_guide/installation_maxwell.html) and
[Perlmutter (NERSC)](https://optimas.readthedocs.io/en/latest/user_guide/installation_perlmutter.html).
diff --git a/doc/source/user_guide/dependencies.rst b/doc/source/user_guide/dependencies.rst
index 636f75be..843eb680 100644
--- a/doc/source/user_guide/dependencies.rst
+++ b/doc/source/user_guide/dependencies.rst
@@ -7,11 +7,13 @@ Optimas relies on the following packages:
* `jinja2 `_ - Needed to generate simulation scripts from templates.
* `libEnsemble `_ - The backbone of optimas, orchestrates the concurrent evaluation of simulations, the resource detection and allocation, and the communication between simulations and manager.
-* `mpi4py `_ - Python bindings for MPI. Required for launching parallel simulations.
* `pandas `_ - Enable output as pandas DataFrames.
* `pydantic `_ - Input validation and object serialization.
* (optional) `Ax `_ - Algorithms for Bayesian optimization.
+Optional dependencies:
+
+* `mpi4py `_ - Python bindings for MPI. Required for launching parallel simulations.
The installed dependencies will determine which generators are available for use.
See table below for a summary.
diff --git a/doc/source/user_guide/installation_local.rst b/doc/source/user_guide/installation_local.rst
index 8ef70c1a..a5d02fa8 100644
--- a/doc/source/user_guide/installation_local.rst
+++ b/doc/source/user_guide/installation_local.rst
@@ -3,6 +3,8 @@ Installation on a local computer
The recommended approach is to install optimas in a ``conda`` environment.
+Optional: If you intend to run Optimus with an MPI Runner, ``mpi4py`` is required.
+
Install ``mpi4py``
~~~~~~~~~~~~~~~~~~
If your system has already an MPI implementation installed, install ``mpi4py``
diff --git a/pyproject.toml b/pyproject.toml
index 64746d9f..2060b755 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,6 @@ dependencies = [
'libensemble >= 1.3.0',
'jinja2',
'pandas',
- 'mpi4py',
'pydantic >= 2.0',
]
dynamic = ['version']
@@ -36,10 +35,12 @@ test = [
'pytest-mpi',
'ax-platform >=0.5.0',
'matplotlib',
+ 'mpi4py',
]
all = [
'ax-platform >=0.5.0',
- 'matplotlib'
+ 'matplotlib',
+ 'mpi4py',
]
[project.urls]