Calculator Setup¶

Start Simple

Just getting started? Try using the EMT or LJ recipes before worrying about setting up one of the calculators below.

Here, we outline how to ensure that quacc can run the quantum chemistry package of your choosing. You only need to follow the instructions for the code(s) you intend to use.

DFTB+¶

If you plan to use DFTB+ with quacc, you will need to install the code as follows:

conda install -c conda-forge dftbplus

EMT¶

No setup needed!

Gaussian¶

To use quacc with Gaussian, you will need to define the GAUSSIAN_CMD setting to be the path of the Gaussian executable (or the name of the executable if it is already in your PATH). This can be done as described in the section on "Modifying Quacc Settings", such as by defining the following environment variable:

export QUACC_GAUSSIAN_CMD="/path/to/g16"

GULP¶

To use quacc with GULP, you will need to download and compile GULP 6.2+ per the official manual. Then you will define the GULP_CMD setting to be the path of the GULP executable and the GULP_LIB setting to be the path to the GULP force field library. This can be done as described in the section on "Modifying Quacc Settings", such as by defining the following environment variables in your ~/.bashrc:

export QUACC_GULP_CMD="/path/to/gulp"
export QUACC_GULP_LIB="/path/to/gulp-#.#.#/Libraries"

Receive a Compilation Error?

If you receive an error upon compilation, you likely are using an old version of gfortran. Try ./mkgulp_old_gfortran instead of ./mkgulp in the Src directory.

Lennard Jones¶

No setup needed!

MLPs¶

Several pre-trained "universal" machine-learned potentials (MLPs) are natively supported in quacc, including those based on MACE, CHGNet, and M3GNet.

To use these potentials, you will need to install the corresponding packages. This can be done as follows:

pip install quacc[mlp]

NewtonNet¶

If you plan to use NewtonNet with Quacc, you will need to install it prior to use. This can be done as follows:

pip install quacc[newtonnet]

ONETEP¶

If you plan on using ONETEP with quacc, you will need to obtain and install ONETEP. This can be done as described in the How to Get Onetep section of the software documentation.

At minimum, you will need to define and set ONETEP_CMD to be the full path to your ONETEP binary. You can also specify the ONETEP_PP_PATH to be the path to the pseudopotentials. This can be done as described in the section on "Modifying Quacc Settings".

An example is provided below on how to define the commands in your ~/.bashrc:

export ONETEP_CMD="/path/to/onetep/binary"
export ONETEP_PP_PATH="/path/to/my/pseudos"

ORCA¶

To use quacc with ORCA, you will need to define the ORCA_CMD setting to be the full, absolute path to your ORCA executable. This can be done as described in the section on "Modifying Quacc Settings", such as by defining the following environment variable in your ~/.bashrc:

export QUACC_ORCA_CMD="/path/to/orca/orca"

Psi4¶

If you plan to use Psi4 with quacc, you will need to install it prior to use. This can be done as described in the Psi4 installation guide.

Q-Chem¶

If you plan to use Q-Chem with Quacc, you will need to install openbabel. This can be done as follows:

conda install -c conda-forge openbabel

Quantum ESPRESSO¶

To use quacc with Quantum ESPRESSO, you will first need to download and install Quantum ESPRESSO. This can be most easily down as follows:

conda install -c conda-forge qe

You will also need to download the relevant pseudopotentials.

Finally, you will need to define multiple environment variables. This can be done as described in the section on "Modifying Quacc Settings".

At minimum, you should define the ESPRESSO_PSEUDO setting:

export QUACC_ESPRESSO_PSEUDO="/path/to/pseudopotentials"

The various ESPRESSO binaries should be present in your PATH, or you should modify the ESPRESSO_BIN_PATHS quacc setting accordingly.

TBLite¶

If you plan to use TBLite with quacc, you will need to install the tblite interface with ASE support.

CondaPip

pip install -c conda-forge tblite-python

pip install quacc[tblite] # only on Linux

Refer to the TBLite documentation for details on how to parallelize calculations and adjust the memory limits.

VASP¶

To use quacc with VASP, you will need to define several environment variables, as described in the section on "Modifying Quacc Settings". The most important are listed below:

export QUACC_VASP_PARALLEL_CMD="srun -N 2 --ntasks-per-node 24"
export QUACC_VASP_PP_PATH="/path/to/POTCARs"

The VASP_PARALLEL_CMD setting tells Custodian and/or ASE how to parallelize VASP. Note that it does not include the executable.

The VASP_PP_PATH setting should point to the directory containing your VASP pseudopotentials. There should be two subdirectories name potpaw_PBE and potpaw for the PBE and LDA pseudopotentials, respectively. If your pseudopotential directories have a different name, create a symbolic link with the required naming scheme. We recommend setting QUACC_VASP_PP_PATH in your ~/.bashrc file since this rarely changes.

Additional settings can be specified as well, such as the name of the VASP executables if they differ from the default values (i.e. vasp_std, vasp_gam).