Keywords: user_guide

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# 1 Introduction

This guide gives a general overview of the contents and of the installation of QUANTUM ESPRESSO (opEn-Source Package for Research in Electronic Structure, Simulation, and Optimization), version 5.1.

The QUANTUM ESPRESSO distribution contains the core packages `PWscf` (Plane-Wave Self-Consistent Field) and `CP` (Car-Parrinello) for the calculation of electronic-structure properties within Density-Functional Theory (DFT), using a Plane-Wave (PW) basis set and pseudopotentials. It also includes other packages for more specialized calculations:

- `PWneb`: energy barriers and reaction pathways through the Nudged Elastic Band (NEB) method.
- `PHonon`: vibrational properties with Density-Functional Perturbation Theory.
- `PostProc`: codes and utilities for data postprocessing.
- `PWcond`: ballistic conductance.
- `XSPECTRA`: K-edge X-ray adsorption spectra.
- `TD-DFPT`: spectra from Time-Dependent Density-Functional Perturbation Theory.

The following auxiliary packages are included as well:

- `PWgui`: a Graphical User Interface, producing input data files for `PWscf` and some `PostProc` codes.
- `atomic`: atomic calculations and pseudopotential generation.
- `QHA`: utilities for the calculation of projected density of states (PDOS) and of the free energy in the Quasi-Harmonic Approximation (to be used in conjunction with `PHonon`).
- `PlotPhon`: phonon dispersion plotting utility (to be used in conjunction with `PHonon`).

A copy of required external libraries is also included. Finally, several additional packages that exploit data produced by QUANTUM ESPRESSO or patch some QUANTUM ESPRESSO routines can be installed as plug-ins:

- `Wannier90`: maximally localized Wannier functions.
- `WanT`: quantum transport properties with Wannier functions.
- `YAMBO`: electronic excitations within Many-Body Perturbation Theory: GW and Bethe-Salpeter equation.
- `PLUMED`: calculation of free-energy surface through metadynamics.
- `GIPAW` (Gauge-Independent Projector Augmented Waves): NMR chemical shifts and EPR g-tensor.
- `GWL`: electronic excitations within GW Approximation.

Documentation on single packages can be found in the `Doc/` or `doc/` directory of each package. A detailed description of input data is available for most packages in files `INPUT_*.txt` and `INPUT_*.html`.

The QUANTUM ESPRESSO codes work on many different types of Unix machines, including parallel machines using both OpenMP and MPI (Message Passing Interface) and GPU-accelerated machines. QUANTUM ESPRESSO also runs on Mac OS X and MS-Windows machines: see section 2.2. A GPU-enabled version of most important codes is available on GitHub: `https://github.com/fspiga/QE-GPU`.

Further documentation, beyond what is provided in this guide, can be found in:

- the `Doc/` directory of the QUANTUM ESPRESSO distribution;
- the QUANTUM ESPRESSO web site `www.quantum-espresso.org`;
- the archives of the mailing list: See section 1.2, ``Contacts'', for more info.

People who want to contribute to QUANTUM ESPRESSO should read the Developer Manual: `Doc/developer_man.pdf`.

This guide does not explain the basic Unix concepts (shell, execution path, directories etc.) and utilities needed to run QUANTUM ESPRESSO; it does not explain either solid state physics and its computational methods. If you want to learn the latter, you should first read a good textbook, such as e.g. the book by Richard Martin: Electronic Structure: Basic Theory and Practical Methods, Cambridge University Press (2004); or: Density functional theory: a practical introduction, D. S. Sholl, J. A. Steckel (Wiley, 2009); or Electronic Structure Calculations for Solids and Molecules: Theory and Computational Methods, J. Kohanoff (Cambridge University Press, 2006). Then you should consult the documentation of the package you want to use for more specific references.

All trademarks mentioned in this guide belong to their respective owners.

Subsections

- 1.1 People
- 1.2 Contacts
- 1.3 Guidelines for posting to the mailing list
- 1.4 Terms of use

Next: 1.1 People Up: User's Guide for Quantum-ESPRESSO Previous: Contents Contents