lib_pprpa

Library for particle-particle random phase approximation.

Installation

Prerequisites

• PySCF 2.7 or higher, and all dependencies

I don't want to develop the code. I just want to install it.

Clone this repo and run pip install . in your Python environment.

Method 1. Set PYTHONPATH

After cloning the repo, you can set the environment variable PYTHONPATH so that the Python interpreter can find lib_pprpa.

For example, if you cloned the repository in the folder /opt, you could run

export PYTHONPATH=/opt/lib_pprpa:$PYTHONPATH

or put this line in your .bashrc so that it runs at the start of every session.

Method 2. Pip editable installation

If you want to install different versions of lib_pprpa in separate Python environments, or if you don't like environment variables, you can do an editable installation with Pip. This method also works for most Python packages in the wild. Clone the repo and run

pip install -e .

No dependencies will be installed in this step---you have to install them separately.

Method 2 is recommended for new users, as it is standard practice. Consult the pip documentation for further information about command-line options for pip.

Features

• ppRPA excitation energy Spin-restricted (spin-adapted), spin-unrestricted, generalized, fractional-charge Analysis tools: density matrix, natural transition orbital

• ppRPA analytic gradient Spin-restricted (spin-adapted), generalized

• T-matrix for quasiparticle energy Spin-restricted and spin-unrestricted

References

Please cite the following papers in publications utilizing the lib_pprpa package:

• J. Chem. Phys. 164, 144118 (2026)

• Phys. Rev. A 88, 030501(R)

• J. Phys. Chem. A 2023, 127, 37, 7811–7822

Cite the following paper if T-matrix code is used:

• J. Phys. Chem. Lett. 2021, 12, 26, 6203–6210

• J. Phys. Chem. Lett. 2017, 8, 14, 3223–3227