ESPRESSO

Policy

ESPRESSO is available to users at HPC2N. It is open source and free, licenced under GPL (GNU public license). However, the developers would be grateful if any scientific work contains a reference to the QE manifesto.

General

ESPRESSO (opEn Source Package for Research in Electronic Structure, Simulation, and Optimization) is an integrated suite of computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials (both norm-conserving and ultrasoft). 

Description

ESPRESSO can do

• Ground-state calculations
  • Self-consistent total energies, forces, stresses;
  • Electronic minimization with iterative diagonalization techniques, damped-dynamics, conjugate-gradients;
  • Kohn-Sham orbitals;
  • Gamma-point and k-point sampling, and a variety of broadening schemes (Fermi-Dirac, Gaussian, Methfessel-Paxton, and Marzari-Vanderbilt);
  • Separable norm-conserving and ultrasoft (Vanderbilt) pseudo-potentials, PAW (Projector Augmented Waves);
  • Several exchange-correlation functionals: from LDA to generalized-gradient corrections (PW91, PBE, B88-P86, BLYP) to meta-GGA, exact exchange (HF) and hybrid functionals (PBE0, B3LYP, HSE);
  • Hubbard U (LDA+U);
  • Berry's phase polarization;
  • Spin-orbit coupling and noncollinear magnetism;
  • Maximally-localized Wannier functions using WANNIER90 code.
• 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;
• Ab-initio molecular dynamics
  • Car-Parrinello Molecular Dynamics;
    • Microcanonical (Verlet) dynamics;
    • Isothermal (canonical) dynamics - Nosé-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);
• 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 using the GIPAW method;
• Spectroscopic properties
  • K- and L₁-edge X-ray Absorption Spectra (XAS)
  • Electronic excitations with Many-Body Perturbation Theory using YAMBO code.
• Quantum Transport
  • Ballistic Transport using PWCOND module.
  • Coherent Transport from Maximally Localized Wannier Functions using WanT code.

It runs on most platforms and fully exploits math libraries like MKL, ESSL, etc. Go here for more information.

Availability

On HPC2N we have ESPRESSO available as a module on Akka and Abisko.

Usage at HPC2N

To use the espresso module, add it to your environment:

module add espresso 

This sets the path and the needed environment variables. There are several versions. To use a different one than the default, run module avail and look for espresso for the versions available.

Loading the module should set all the needed environmental variables as well as the path to the program. 

You will find a number of examples of how to run ESPRESSO in /lap/espresso/examples

Additional info

Documentation is available on the ESPRESSO homepage. There are a User Guide and a page with tutorials and examples.