By Paolo Giannozzi1,2, Stefano Baroni1,3, Nicola Bonini4, Matteo Calandra5, Roberto Car6, Carlo Cavazzoni7,8, Davide Ceresoli4, Guido L Chiarotti9, Matteo Cococcioni10, Ismaila Dabo11, Andrea Dal Corso1,3, Stefano de Gironcoli1,3, Stefano Fabris1,3, Guido Fratesi12, Ralph Gebauer1,13, Uwe Gerstmann14, Christos Gougoussis5, Anton Kokalj1,15, Michele Lazzeri5, Layla Martin-Samos1, Nicola Marzari4, Francesco Mauri5, Riccardo Mazzarello16, Stefano Paolini3,9, Alfredo Pasquarello17,18, Lorenzo Paulatto1,3, Carlo Sbraccia1,20, Sandro Scandolo1,13, Gabriele Sclauzero1,3, Ari P Seitsonen5, Alexander Smogunov13, Paolo Umari1 and Renata M Wentzcovitch10,19
Quantum ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave). The acronym ESPRESSO stands for opEn Source Package for Research in Electronic Structure, Simulation, and Optimization. It is freely available to researchers around the world under the terms of the GNU General Public License. Quantum ESPRESSO builds upon newly-restructured electronic-structure codes that have been developed and tested by some of the original authors of novel electronic-structure algorithms and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency are still its main focus, with special attention paid to massively parallel architectures, and a great effort being devoted to user friendliness. Quantum ESPRESSO is evolving towards a distribution of independent and interoperable codes in the spirit of an open-source project, where researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.