Quantum ESPRESSO

Key information

• Mostly written in modern Fortran.

• Supports standard GGA and many advanced functionals such as non-local vdW-enabled, meta-GGA, Hubbard-corrected, hybrid functionals. It can be linked with Libxc and use all functionals implemented there.

• Performs many types of ground-state calculations: self-consistent energies, forces and stresses, structural optimization, molecular dynamics (PW and CP); search for transition pathways (NEB).

• Contains routines and methods for the computation of the linear response to external perturbations. These are used for computing dielectric responses and vibrational spectra (PHonon); optical, magnons, and EELS spectra, using time-dependent DFT (TDDFPT); electron-phonon coupling coefficients and related properties (EPW); self consistent Hubbard correction parameters (HP), and more.

• Used as a starting point for workflows that implement advanced methodologies such as MBPT, QMC, DMFT, and others.

Features

• PWscf: structural optimisation and molecular dynamics on the electronic ground state, with self-consistent solution of DFT equations

  • Total energy, forces, stress

  • Collinear and noncollinear magnetism, spin-orbit coupling

  • Structural optimisation and Born-Oppenheimer molecular dynamics;

  • Berry-Phase

• CP: Car-Parrinello molecular dynamics;

• PWneb: reaction pathways and transition states with the Nudged Elastic Band method;

• PHonon: vibrational and dielectric properties from Density-Functional Perturbation Theory;

• EPW: calculation of electron-phonon coefficients in metals;

• GWL: many-body perturbation theory in the GW approach using ultra-localised Wannier functions and Lanczos chains.

Libraries

The code source is hosted on the GitHub hosting service. It works with Fortran and C compilers and takes advantage of highly optimized libraries such as BLAS, LAPACK, SCALAPACK, FFTW3, HDF5, GDLib and GSL.

I/O requirements

Electronic structure data, like for instance the wavefunctions, are written and read by Quantum ESPRESSO PWscf executable using a direct access to file: each task uses a raw format to store its information. These files can be used to produce checkpoints (restart).

Diffusion

Quantum ESPRESSO is released under the GPL license. It has a sizeable basis of users, as apparent from the number of citations of the two documenting papers of 2009 [1] (16,000+) and 2017 [2] (2,500+), authored by 25,000+ scientists and by the number of messages exchanged on the users’ mailing list (2000+/year). In addition to the inner circle of developers (~20), Quantum ESPRESSO often receives contributions from external users and developers. There are currently 107 forks of the main GitLab repository, and 243 of the GitHub mirror. We are aware of at least 12 independent successful software projects that rely entirely on Quantum ESPRESSO technology and codebase for further development.

References

[1] P. Giannozzi, S. Baroni, N. Bonini et al: Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials. Journal of Physics: Condensed Matter, 21, 39, 2009.

[2] P. Giannozzi, O. Andreussi, T. Brumme, O. Bunau, M. B. Nardelli, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, et al., Advanced capabilities for materials modelling with Quantum ESPRESSO, J. Phys.: Condens. Matter 29, 465901 (2017).