Overview:

Quantum Espresso is an plane wave density functional code for electronic structure calculations and materials modeling at the nanoscale.  It can make use of both norm-conserving and ultrasoft pseudopotentials.

IWCE Phonon School Tutorial Files   Handout1  Handout2

Applications :

Ground-state calculations:

• Self-consistent total energies, forces, stresses;
• Electronic minimization with iterative diagonalization techniques, damped-dynamics, conjugate-gradients;
• Separable norm-conserving and ultrasoft (Vanderbilt) pseudo-potentials, PAW (Projector Augmented Waves)
• Hubbard U (LDA+U);
• Berry's phase polarization;
• Spin-orbit coupling and noncollinear magnetism;
• Maximally-localized Wannier functions.
• Response properties (density-functional perturbation theory):
  
• Phonon frequencies and eigenvectors at any wavevector;
• Full phonon dispersions; inter-atomic force constants in real space;
• Translational and rotational acoustic sum rules; Effective charges and dielectric tensors;
• Electron-phonon interactions; Third-order anharmonic phonon lifetimes;
• Infrared and (non-resonant) Raman cross-sections; EPR and NMR chemical shifts;
• Spectroscopic properties:
  
• K- and L₁-edge X-ray Absorption Spectra (XAS)
• Ab-initio molecular dynamics
  
• Car-Parrinello Molecular Dynamics;
• Microcanonical (Verlet) dynamics;
• Isothermal (canonical) dynamics - Nose-Hoover thermostats and chains;
• Isoenthalpic, variable cell dynamics (Parrinello-Rahman);
• Constrained dynamics;
• Born-Oppenheimer Molecular Dynamics;
• Microcanonical (Verlet) dynamics;
• Isothermal (canonical) dynamics - Anderson, Berendsen thermostats;
• Isoenthalpic, variable cell dynamics (Parrinello-Rahman);
• Constrained dynamics; Ensemble-DFT dynamics (for metals/fractional occupations);
• Structural Optimization:
  
• GDIIS with quasi-Newton BFGS preconditioning;
• Damped dynamics; Ionic conjugate-gradients minimization;
• Projected velocity Verlet;
• Transition states and minimum energy paths:
• Born-Oppenheimer nudged elastic band;
• Born-Oppenheimer string dynamics;

Quantum Espresso has been developed primarily at the DEMOCRITOS National Simulation Center in Trieste, Italy.  Other partner organizations that have contributed to code development include CINECA National Supercomputing Center (Bolgna, Italy), the Ecole Polytechnique Federale de Lausanne, MIT, and Princeton University.

Key developers include:

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, G. L. Chiarotti, M. Cococcioni, I. Dabo, A. Dal Corso, S. Fabris, G. Fratesi, S. de Gironcoli, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A. P. Seitsonen, A. Smogunov, P. Umari, R. M. Wentzcovitch

Getting Started:

• Quantum Espresso Main Page
• Quantum Espresso Manual
• 2012 PASI Workshop "Computational Material Science for Energy Generation and Conversion".  The workshop schedule contains Quantum Espresso tutorials on general use, magnetic systems, and calculating phonon properties.
  
• NSF/Democritos Summer School on Materials Modeling from First-Principles: Theory and Practice, Santa Barbara, July 2009. Videos for all lectures available at http://media.quantum-espresso.org
• Quantum Espresso Survival Guide from the Materials Computation Center 2006 Summer School on Computational Materials Science, with Lecture videos.
  
• Building Nanostructures Bit by Bit Lectures and Tutorials from the 2006 Cornell Nanoscale Facility Fall Modeling Workshop. This contains general information on plane wave approaches, classical and car-parrinello molecular dynamics.

Relevant Research Articles and Webpages:

• "QUANTUM ESPRESSO: a modular and open source software project for quantum simulations of materials", P. Giannozzi et al., Journal of Physics: Condensed Matter, 21, 395502 (2009).
• "A pseudopotential plane waves program (pwscf) and some case studies", Lecture Notes in Chemistry, 67, ed C. Pisani (Berlin: Springer) (1996). [A very early description of the core code]
• Quantum Espresso Wiki
• Scientific Papers by year resulting from Quantum Espresso.
  
• Search the Quantum Espresso user forum for help with a problem.
  

Questions, Comments...

Please contact:

Derek Stewart, Ph.D.
stewart (at) cnf.cornell.edu
Cornell Nanoscale Facility