> For the complete documentation index, see [llms.txt](https://docs.ccv.brown.edu/oscar/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ccv.brown.edu/oscar/local-install/installing-your-own-version-of-quantum-espresso.md).

# Installing your own version of Quantum Espresso

These instructions are for users who need to install their own version of Quantum Espresso.

{% hint style="warning" %}
Do not load the 'quantumespresso' module. If you have a 'quantumespresso' module loaded, unload it:

`module unload`quantumespresso
{% endhint %}

Step 1: Create a new directory where you want to install Quantum Espresso:

```bash
mkdir -p quantum-espresso/src
cd quantum-espresso/src/
```

Step 2: Download the version of Quantum Espresso you want from the GitHub repo:

```bash
https://github.com/QEF/q-e/releases
wget https://github.com/QEF/q-e/archive/refs/tags/qe-6.4.tar.gz
tar xvf qe-6.4.tar.gz
cd q-e-qe-6.4/
```

Step 3: Load the newer compiler module and configure it with custom flags.

```bash
module load intel/2020.2
CC=icc CXX=icpc F77=ifort FC=ifort ./configure --prefix=/users/<username>/data/quantum-espresso/
```

* Configuration options
  * Compiling with MPI

    ```bash
    module load mpi/<version>
    # load the mpi module dependencies
    CC=icc CXX=icpc F77=ifort FC=ifort ./configure --prefix=/users/<username>/data/quantum-espresso/
    ```
  * Compiling with optimized libraries (boost & hdf5)

    ```bash
    module load mpi/<version>
    module load hdf5/1.10.5_fortran fftw/3.3.6
    # load the mpi module dependencies
    CC=icc CXX=icpc F77=ifort FC=ifort ./configure --prefix=/users/<username>/data/quantum-espresso/ --with-hdf5=/oscar/runtime/opt/hdf5/1.10.5_fortran LIBDIRS=/oscar/runtime/opt/fftw/3.3.6/lib
    ```

More configuration options can be found [in the Quantum Espresso user guide](http://www.quantum-espresso.org/Doc/user_guide/node7.html).

{% hint style="warning" %}
The --prefix PATH will be replaced by your custom install location
{% endhint %}

Step 4: If you are happy with the configure flags then install them by:

```bash
make
make install
```

Step 5 (Optional): Adding QuantumEspresso to your path

Add the following lines to your \~/.bashrc

```bash
export PATH=/users/<username>/data/quantum-espresso/bin:$PATH
export BIN_DIR=/users/<username>/data/quantum-espresso/bin
```

Restart the Oscar session or `source .bashrc`

## Installing custom Addon patches for Quantum Espresso

There are various addons available for Quantum Espresso, in this tutorial, we will install [Environ](https://environ.readthedocs.io/en/latest/) - a computational library aimed at introducing environment effects to atomistic first-principles simulations.

The source code can be obtained from [the CIME\_Oscar GitHub repository](https://github.com/brown-ccv/CIME_Oscar). The easiest way to incorporate these files into your build is to place them in the root directory of Quantum Espresso (\~/data/quantum-espresso/src/q-e-qe-6.4). For example:

```bash
git clone https://gitlab.com/olivieroandreussi/Environ.git
```

1. Run the QE script addonpatch.sh with the -patch option:

   ```bash
   ./install/addsonpatch.sh Environ Environ/src Modules -patch
   ```
2. Run the Environ installation script with the -patch option:

   ```bash
   ./Environ/patches/environpatch.sh -patch
   ```
3. Run the QE script to regenerate modules’ dependencies:

   ```bash
   ./install/makedeps.sh
   ```
4. Re-compile, e.g.:

   ```bash
   make pw
   ```

## Installing with QMCPACK

1. Download QMCPACK:

   ```bash
   git clone https://github.com/QMCPACK/qmcpack.git
   ```
2. Copy `*.diff` and `*.sh` files from qmcpack to QE/src folder
3. Patch QuantumEspresso:

   ```bash
   ./download_and_patch_qe6.4.sh
   ```
4. Follow the steps above for Installing Quantum Espresso