There are many ways for installing Reaktoro, from a simple single-line terminal command to building the entire project from sources. All current possibilities are detailed below.

Installation using Conda

Reaktoro can be easily installed using Conda, a powerfull package manager used to simplify Reaktoro’s installation and the management of its external software dependencies. Once you install Conda, and append the necessary channels, you’ll be able to install Reaktoro by just executing the following command in your terminal:

conda install reaktoro

Follow the Conda installation steps shown next before you execute this command!

Installing Conda

Conda can be installed by installing either Anaconda or Miniconda. We recommend the installation of Miniconda, unless you already have Anaconda installed or you think you need 1,400+ software packages that ship with it! Miniconda is just a tiny subset of Anaconda containing only our needed conda application and its dependencies.

Download the Miniconda Installer by clicking on the image below:


Reaktoro is a proud user of Conda, a powerfull and modern package manager!

You’ll be given options to install Miniconda for Windows, Mac OS X, and Linux (32-bit or 64-bit) using either Python 3.7 or Python 2.7. We recommend a 64-bit installer of Miniconda with Python 3.7.

Adding conda-forge channels

The Reaktoro pre-built package is hosted on conda-forge. After installing Miniconda, go to a terminal and execute:

conda config --append channels conda-forge

to add the conda-forge channels required to find the Reaktoro package.

All should now be set to install Reaktoro using:

conda install reaktoro

Go to Reporting a failed installation if this does not work for you.

Installation using CMake

Reaktoro has several software and library dependencies that need to be pre-installed for its successful compilation and installation using CMake. To greatly simplify the building process of Reaktoro for Windows, Mac OS X, and Linux, you’ll need Conda. Follow the Conda installation steps in the previous section, in which a Miniconda installer is used.

After installing Miniconda, go to a terminal and execute:

conda install -n base conda-devenv

This installs conda-devenv, a conda tool with convenient functionalities to define and initialize conda environments.

Downloading Reaktoro from GitHub

We need now to download the source code of Reaktoro, which is hosted on GitHub. This can be done by either executing the following git command from the terminal (if you already have git installed!):

git clone

or by directly downloading, the latest version of Reaktoro’s source code in a zip file.


If you use the direct download option above, please unzip the downloaded file in a directory of your choice. We assume the unzipped folder is named reaktoro for the next installation steps, and not reaktoro-master.

Creating a conda environment for Reaktoro

The next step is to create a conda environment that contains all the software and library dependencies needed to build Reaktoro. In the root of the reaktoro directory, execute:

conda devenv

This command will create the conda environment called reaktoro, which can take a few minutes to complete for the first time.


You only need to execute conda devenv again when the list of external dependencies changes or some configuration in the conda environment reaktoro is altered.


If you are curious about the list of dependencies needed to build Reaktoro, have a look at the file environment.devenv.yml in the root directory of Reaktoro’s source code. This file is a recipe for the creation of our conda environment reaktoro containing all required dependencies.

Activating the conda environment for Reaktoro

The next step is to activate the conda environment reaktoro that conda-devenv created for us:

conda activate reaktoro


You need to activate the reaktoro conda environment whenever you use Reaktoro from C++ or Python! This is because conda will adjust some environment variables in your system (e.g., PYTHONPATH, LD_LIBRARY_PATH, PATH) so that Reaktoro’s libraries, executables, and Python packages can be found. Activating the reaktoro conda environment is the simplest way to get these environment variables set correctly.

Building and installing Reaktoro with CMake

You can now build and install Reaktoro by executing the following from the root of the reaktoro source directory:

cmake -P install

Assuming the conda environment reaktoro is active, this command will first build Reaktoro and then install its header files, libraries, executables, Python package in your local miniconda directory:


Alternatively, to build and install Reaktoro in a more traditional way, execute the following from the root directory of Reaktoro’s source code:

mkdir build
cd build
cmake ..
cmake --build . --target install

The following is also possible with CMake v3.13 or newer:

cmake -S . -B build
cmake --build build/ --target install


Compiling the Reaktoro C++ library and the Reaktoro Python module should take a few minutes for the first time. However, if you activate the reaktoro conda environment, ccache will be used to significantly speed up future compilations automatically for you!

Installing Reaktoro in a custom directory

To install Reaktoro in a different directory, say, /home/user/other, use:

cmake -DPREFIX=/home/user/other -P install


cmake .. -DCMAKE_INSTALL_PREFIX=/home/user/other
cmake --build . --target install

You’ll need, however, to set the environment variables PYTHONPATH, LD_LIBRARY_PATH, and PATH yourself. For example, in Linux:

export PATH=$PATH:/home/user/other/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/user/other/lib{64}
export PYTHONPATH=$PYTHONPATH:/home/user/other/lib{64}/pythonX.Y/site-packages

where lib{64} is either lib or lib64, and pythonX.Y where pythonX.Y depends on the python version used to compile Reaktoro’s Python package (e.g., python3.6, python3.7).

Checking for a successful installation

Check if Reaktoro was installed correctly by executing:

python -c 'import reaktoro; print(reaktoro.__path__[0])'

This should print the path to the installed python package reaktoro. For example:


where pythonX.Y above depends on the python version used.


Make sure you have the conda environment reaktoro active! Otherwise the checking above might not work without further actions (e.g., changing the PYTHONPATH environment variable).

If you get instead something like:

Traceback (most recent call last):
    File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'reaktoro'

then the installation was not successful or it was installed in a custom path that is not yet given in the PYTHONPATH environment variable.

Reporting a failed installation

A failed installation can be a frustating emotion, but we will be happy to help you fixing your installation issue. However, please do make sure you followed exactly the steps given before. If you are sure that you followed every single instruction and the installation still fails, please go to:

Reaktoro’s GitHub Issues

and let us know!