Quick Install Guide¶

This quick install guide outlines the basic steps needed to install OpenMC on your computer. For more detailed instructions on configuring and installing OpenMC, see Installation and Configuration in the User’s Manual.

Installing on Linux/Mac with Mamba and conda-forge¶

Conda is an open source package management system and environments management system for installing multiple versions of software packages and their dependencies and switching easily between them. Mamba is a cross-platform package manager and is compatible with conda packages. OpenMC can be installed in a conda environment with mamba. First, conda should be installed with one of the following installers: Miniconda, Anaconda, or Miniforge. Once you have conda installed on your system, OpenMC can be installed via the conda-forge channel with mamba.

First, add the conda-forge channel with:

conda config --add channels conda-forge

Then create and activate a new conda enviroment called openmc-env in which to install OpenMC.

conda create -n openmc-env
conda activate openmc-env

Then install mamba, which will be used to install OpenMC.

conda install mamba

To list the versions of OpenMC that are available on the conda-forge channel, in your terminal window or an Anaconda Prompt run:

mamba search openmc

OpenMC can then be installed with:

mamba install openmc

You are now in a conda environment called openmc-env that has OpenMC installed.

Installing on Linux/Mac/Windows with Docker¶

OpenMC can be easily deployed using Docker on any Windows, Mac, or Linux system. With Docker running, execute the following command in the shell to download and run a Docker image with the most recent release of OpenMC from DockerHub:

docker run openmc/openmc:latest

This will take several minutes to run depending on your internet download speed. The command will place you in an interactive shell running in a Docker container with OpenMC installed.

Note

The docker run command supports many options for spawning containers including mounting volumes from the host filesystem, which many users will find useful.

Installing from Source using Spack¶

Spack is a package management tool designed to support multiple versions and configurations of software on a wide variety of platforms and environments. Please follow Spack’s setup guide to configure the Spack system.

To install the latest OpenMC with the Python API, use the following command:

spack install py-openmc

For more information about customizations including MPI, see the detailed installation instructions using Spack. Once installed, environment/lmod modules can be generated or Spack’s load feature can be used to access the installed packages.

Manually Installing from Source¶

Obtaining prerequisites on Ubuntu¶

When building OpenMC from source, all prerequisites can be installed using the package manager:

sudo apt install g++ cmake libhdf5-dev libpng-dev

After the packages have been installed, follow the instructions to build from source below.

Obtaining prerequisites on macOS¶

For an OpenMC build with multithreading enabled, a package manager like Homebrew should first be installed. Then, the following packages should be installed, for example in Homebrew via:

brew install llvm cmake xtensor hdf5 python libomp libpng

The compiler provided by the above LLVM package should be used in place of the one provisioned by XCode, which does not support the multithreading library used by OpenMC. Consequently, the C++ compiler should explicitly be set before proceeding:

export CXX=/opt/homebrew/opt/llvm/bin/clang++

After the packages have been installed, follow the instructions to build from source below.

Building Source on Linux or macOS¶

All OpenMC source code is hosted on GitHub. If you have git, a modern C++ compiler, CMake, and HDF5 installed, you can download and install OpenMC by entering the following commands in a terminal:

git clone --recurse-submodules https://github.com/openmc-dev/openmc.git
cd openmc
mkdir build && cd build
cmake ..
make
sudo make install

This will build an executable named openmc and install it (by default in /usr/local/bin). If you do not have administrator privileges, the cmake command should specify an installation directory where you have write access, e.g.

cmake -DCMAKE_INSTALL_PREFIX=$HOME/.local ..

The openmc Python package must be installed separately. The easiest way to install it is using pip. From the root directory of the OpenMC repository, run:

python -m pip install .

By default, OpenMC will be built with multithreading support. To build distributed-memory parallel versions of OpenMC using MPI or to configure other options, directions can be found in the detailed installation instructions.